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['Konig, Oliver', 'Fadel, Georges M.'] | 2019-03-12T16:41:02Z | 2019-03-12T16:41:02Z | 1999 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/73599', 'http://dx.doi.org/10.26153/tsw/741'] | eng | 1999 International Solid Freeform Fabrication Symposium | Open | ['FE"\'analysis', 'DOF'] | Application of Genetic Algorithms in the Design of Multi-Material Structures Manufactured in Rapid Prototyping | Conference paper | https://repositories.lib.utexas.edu//bitstreams/291ae70f-08c4-4f8d-b4c7-92faa047deea/download | null | Recent developments in the Rapid Prototyping technology establish it as a new
manufacturing technique, enabling localized material addition to build a part. Thus,
heterogeneous structures, consisting of more than one material can be produced. The aim of this
paper is to present an optimization tool to find the best material distribution in a multi-material
structure due to given objectives and constraints. The tool is based on genetic algorithms using a
discrete material model and FE"'analysis to evaluate the objective functions. It can optimize the
distribution materials in 2D-structures with up to 1500 DOF's at reasonable
computational costs. Its performance is shown on a bi-objective optimization of a turbine blade. | null | null | null | null | null | null |
['Ouyang, J.H.', 'Mei, H.', 'Valant, M.', 'Kovacevic, R.'] | 2019-10-22T18:00:05Z | 2019-10-22T18:00:05Z | 2002 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/76327', 'http://dx.doi.org/10.26153/tsw/3416'] | eng | 2002 International Solid Freeform Fabrication Symposium | Open | Welding | Application of Laser-Based Additive Manufacturing to Production of Tools for Friction Stir Welding | Conference paper | https://repositories.lib.utexas.edu//bitstreams/91806466-1b99-4271-88d2-92922407539c/download | null | This paper presents a feasibility study of application of laser-based additive
manufacturing to production of tools for friction-stir welding (FSW) of materials. The design
and rapid manufacturing of powerful tools has become one of the major challenges in expanding
the application of FSW processes to new materials. The one-step laser cladding process is
capable of creating a novel, fully dense and metallurgically bonded near-net-shape tool with
microstructural and compositional gradients. In this paper, two kinds of FSW-tool materials are
developed and evaluated for the applications of welding different materials. A pure H13 tool
steel powder is used to build a FSW-tool for welding the materials with relatively low melting
temperatures, such as aluminum alloys. A WC-based ceramet/tool steel functionally graded
material (FGM) is synthesized to build a FSW-tool in order to weld the materials with higher
melting temperatures and highly abrasive materials such as MMC materials. By controlling the
amount of different supplied powders under the optimized laser cladding conditions, WC-based
ceramet/tool steel FGMs are successfully synthesized layer by layer. FSW experiments are
carried out to evaluate the deposited tools. | This work was financially supported by THECB, Grants 003613-0022-1999, 003613-
0016-2001, NSF Grants No. DMI-9732848 and DMI-9809198, and the U.S. Department of
Education, Grant No. P200A80806-98. | null | null | null | null | null |
['Malone, Evan', 'Purwin, Oliver'] | 2020-02-13T21:02:36Z | 2020-02-13T21:02:36Z | 2004 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/79979', 'http://dx.doi.org/10.26153/tsw/7004'] | eng | 2004 International Solid Freeform Fabrication Symposium | Open | viscosity | Application of Machine Learning Methods to the Open-Loop Control of a Freeform Fabrication System | Conference paper | https://repositories.lib.utexas.edu//bitstreams/d0605853-f5c0-4975-97fc-4e35567e1659/download | null | Freeform fabrication of complete functional devices requires the fabrication system to achieve well-controlled
deposition of many materials with widely varying material properties. In a research setting, material preparation
processes are not highly refined, causing batch property variation, and cost and time may prohibit accurate
quantification of the relevant material properties, such as viscosity, elasticity, etc. for each batch. Closed-loop
control based on the deposited material road is problematic due to the difficulty in non-contact measurement of the
road geometry, so a labor-intensive calibration and open-loop control method is typically used. In the present work,
k-Nearest Neighbor and Support Vector Machine (SVM) machine learning algorithms are applied to the problem of
generating open-loop control parameters which produce desired deposited material road geometry from a description
of a given material and tool configuration comprising a set of qualitative and quantitative attributes. Training data
for the algorithms is generated in the course of ordinary use of the SFF system as the results of manual calibration of
control parameters. Given the large instance space and the small training data set compiled thus far, the
performance is quite promising, although still insufficient to allow complete automation of the calibration process.
The SVM-based approach produces tolerable results when tested with materials not in the training data set. When
control parameters produced by the learning algorithms are used as a starting point for manual calibration,
significant operator time savings and material waste reduction may be achieved. | null | null | null | null | null | null |
['Hasan, S.', 'Rennie, A.E.W.'] | 2021-09-23T22:45:10Z | 2021-09-23T22:45:10Z | 2008 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88044', 'http://dx.doi.org/10.26153/tsw/14985'] | eng | 2008 International Solid Freeform Fabrication Symposium | Open | ['Rapid Manufacturing', 'spare parts industry', 'e-business'] | The Application of Rapid Manufacturing Technologies in the Spare Parts Industry | Conference paper | https://repositories.lib.utexas.edu//bitstreams/08d8f05a-05c0-4aa6-910e-7fa8aeec1020/download | null | null | null | text | null | null | null | null |
['Bharadwaja, R.', 'Murugan, Aravind', 'Chen, Yitao', 'Liou, F W'] | 2021-11-18T18:26:50Z | 2021-11-18T18:26:50Z | 2019 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90457', 'http://dx.doi.org/10.26153/tsw/17378'] | eng | 2019 International Solid Freeform Fabrication Symposium | Open | ['schlieren', 'visualization', 'shielding gas', 'additive manufacturing'] | Application of Schlieren Technique in Additive Manufacturing: A Review | Conference paper | https://repositories.lib.utexas.edu//bitstreams/c6765b25-515a-4723-8c53-66123153de35/download | University of Texas at Austin | Additive manufacturing has gained a lot of attention in the past few decades due to its
significant advantages in terms of design freedom, lower lead time, and ability to produce complex
shapes. One of the pivotal factors affecting the process stability and hence the part quality is the
shielding gas flow in additive manufacturing. As extremely beneficial for the process, the shielding
gas flow is often set at maximum supply to achieve enough gas cover over the substrate. This
causes excessive quantity of shielding gas to be unutilized. Realizing the importance of shielding
gas, various studies have been carried out to monitor and visualize the shielding gas, and one such
technique is Schlieren imaging. Schlieren visualization has been used since the 1800s as a powerful
visualization tool to visualize fluctuations in optical density. The Schlieren technique is highly
effective for visualizing and optimizing shielding gas flow. This paper aims to provide an overview
of Schlieren technique used for visualization of shielding gas and highlights the application of
Schlieren in additive manufacturing. | null | null | null | null | null | null |
['Harryson, Ola', 'Cormier, Denis', 'Marcellin-Little, Denis', 'Jaja, Ketan'] | 2019-10-22T17:36:22Z | 2019-10-22T17:36:22Z | 2002 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/76322', 'http://dx.doi.org/10.26153/tsw/3411'] | eng | 2002 International Solid Freeform Fabrication Symposium | Open | Preoperative Pllanning | Application of SFF to Preoperative Planning and Surgical Rehearsal for Treatment of Limb Deformities in Dogs | Conference paper | https://repositories.lib.utexas.edu//bitstreams/eeb250cc-9bf1-47b5-b400-9b79cae2bd1a/download | null | This report describes SFF-aided assessment and preoperative planning for treatment of
bilateral multifocal pelvic limb deformities in a one-year old German Shepherd dog. CT scans
were converted to solid models and stereolithography patterns were prototyped. RTV silicone
molds were constructed and three sets of polyurethane patterns were cast for pre-surgical
rehearsal. The paper compares traditional osteotomy planning procedures, planning via virtual
prototypes, and planning with full-scale physical prototypes. | null | null | null | null | null | null |
['Kinsella, M.E.', 'Lilly, B.W.', 'Bhagavatula, N.', 'Cooper, K.G.'] | 2019-10-22T18:07:57Z | 2019-10-22T18:07:57Z | 2002 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/76330', 'http://dx.doi.org/10.26153/tsw/3419'] | eng | 2002 International Solid Freeform Fabrication Symposium | Open | Quantities | Application of Solid Freeform Fabrication Processes for Injection Molding Low Production Quantities: Process Parameters and Ejection Force Requirements for SLS Inserts | Conference paper | https://repositories.lib.utexas.edu//bitstreams/8acf9c49-e28c-4c8b-8d95-d5068e419d12/download | null | Studies are underway for the application of solid freeform fabrication processes for mold
inserts to be used in thermoplastic injection molding of low quantities of parts. This work
initially compares a laser sintered insert (LaserForm™ ST-100) with a steel insert. Models and
experiments determine process parameters, including molding latitude, and ejection force
requirements. Ejection force predictions are based on work by Menges, using values for elastic
modulus determined from tensile tests at ejection temperatures. Similar studies are planned for
stereolithography inserts (SL 5170). | null | null | null | null | null | null |
['Jayanthi, Suresh', 'Harwin, William', 'Keefe, Michael', 'Kumar, Vijay'] | 2018-11-02T16:16:03Z | 2018-11-02T16:16:03Z | 1995 | Mechanical Engineering | doi:10.15781/T21R6NK6M | http://hdl.handle.net/2152/69334 | eng | 1995 International Solid Freeform Fabrication Symposium | Open | ['stereolithography', 'cerebral palsy', 'rehabilitation engineering'] | Application of Stereolithography in the Fabrication of Rehabilitation Aids | Conference paper | https://repositories.lib.utexas.edu//bitstreams/e00c1557-6072-4ac7-aeaf-9b1265e927e3/download | null | Free form fabrication methods have a great potential to significantly
improve the design and manufacture of equipment for people
with physical disabilities, such as quadriplegia through spinal cord injury,
arthrogryposis, or cerebral palsy. Depending on the nature of
the disability a device may need to be designed or adapted. A person
with quadriplegia, for example, may benefit from an assistive device
that maps existing head movements, into the movements of a spoon
between a plate and his/her mouth. To be comfortable and effective
a person Iuay need a headband that can connect to a suitable linkage.
Stereolithography lends itself well to the fabrication of such one-of-akind
devices. Since the fabrication process time is considerably less
than conventional approaches a greater number of iterations can be
performed during the design to arrive at the most compatible device
for a particular disability. Some rehabilitation devices are fabricated
to establish the viability and linlitations of this approach. This paper
details the efforts underway to integrate stereolithography with the
needs of rehabilitation engineering. | null | null | null | null | null | null |
['Fisher, Joseph W.', 'Simpson, Timothy W.', 'Miller, Simon W.'] | 2023-03-01T17:15:32Z | 2023-03-01T17:15:32Z | 2022 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/117548', 'http://dx.doi.org/10.26153/tsw/44428'] | eng | 2022 International Solid Freeform Fabrication Symposium | Open | Lattice Structure | Application of Systems Engineering to Lattice Structure Design: A Framework for Requirements Flow Down | Conference paper | https://repositories.lib.utexas.edu//bitstreams/2516141b-ebf3-47e3-aa00-bc4446fccb65/download | null | In the field of additive manufacturing, highly ordered cellular structures with repeating
patterns in space, known as lattice structures or simply “lattices”, have been shown to sig-
nificantly improve the performance per unit mass of engineered components compared to
traditionally machined designs. The characteristics of these lattices are dependent on many
design decisions, leading to challenges in determining how to best utilize them. This issue
is further complicated when the density, size, and topology of the lattice can spatially vary
in the design domain. Many methods have been proposed to optimally distribute material
within a lattice structure; however, these methods exist in a bubble, independent of broader
engineering design criteria and processes. In this paper, we introduce a framework based on
systems engineering to guide the design of lattice structures using the component requirements
as inputs and outputting a verified and validated design based on those requirements. The
framework translates component requirements down to the lattice structure and provides a
means to verify and validate that the final design meets those requirements. We provide a
walk-through of the framework by designing a lattice structure for an oil and gas component,
and discuss future research to extend, verify, and validate the framework. | null | null | null | null | null | null |
['Adnan, Muhammad', 'Lu, Yan', 'Jones, Al', 'Cheng, Fan Tien'] | 2021-11-16T16:25:11Z | 2021-11-16T16:25:11Z | 2019 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90334', 'http://dx.doi.org/10.26153/tsw/17255'] | eng | 2019 International Solid Freeform Fabrication Symposium | Open | ['additive manufacturing', 'fog computing', 'monitoring & control', 'functional architecture', 'control architecture', 'data analytics'] | Application of the Fog Computing Paradigm to Additive Manufacturing Process Monitoring and Control | Conference paper | https://repositories.lib.utexas.edu//bitstreams/2d04ea32-cba5-4730-ba23-e3603beabaf8/download | University of Texas at Austin | Monitoring and controlling Additive Manufacturing (AM) processes play a critical role in
enabling the production of quality parts. AM processes generate large volumes of structured and
unstructured in-situ measurement data. The ability to analyze this volume and variety of data in
real-time is necessary for effective closed-loop control and decision-making. Existing control
architectures are unable to handle this level of data volume and speed. This paper investigates the
functional and computational requirements for real-time closed-loop AM process control. The
paper uses those requirements to propose a function architecture for AM process monitoring and
control. That architecture leads to a fog-computing solution to address the big data and real-time
control challenges. | null | null | null | null | null | null |
['Chahine, Gilbert', 'Smith, Pauline', 'Kovacevic, Radovan'] | 2021-09-30T19:14:49Z | 2021-09-30T19:14:49Z | 2010 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88284', 'http://dx.doi.org/10.26153/tsw/15225'] | eng | 2010 International Solid Freeform Fabrication Symposium | Open | ['topology optimization', 'modern additive manufacturing', 'Electron Beam Melting', 'functionally graded porosity', 'bio-adaptable dental implants'] | Application of Topology Optimization in Modern Additive Manufacturing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/350d3d4c-51e8-48a0-9556-0af9dbbf25e7/download | University of Texas at Austin | The current work examines the principle of topology optimization (TOP) and solving the problem
of minimal compliance, and its applications in modern additive manufacturing (AM). The theory of TOP
has been excessively investigated for the past few decades; however its practical use is hindered by
manufacturing limitations of manifesting the designs into physical parts. TOP numerically determines the
favorable topology configuration contained in a workspace that is constrained by a specific set of
external supports and applied loads. It overcomes conventional design traditions, and solves for finding
the path of least resistance, mimicking phenomenon found in natural structures, such as bone and wood.
The present research focuses on the different methodologies invested in the field, and also inspects the
possibilities and efficiency of using numerical design, which is powered by TOP, in modern AM processes
such as Electron Beam Melting enabling the production of highly complex parts. The major interest is the
production of functionally graded porosity (FGP) in bio-adaptable dental implants able to reduce stress
shielding, promote faster osseointegration, and provide micromotion between the dental prosthesis and
the root form of the implant. Future implications of the field include optimized porous structures aiming
towards application-defined stiffness and pore size, enabling a digital design with advances analogous to
modern AM. | null | null | null | null | null | null |
Winkelman, Wayne | 2018-10-03T16:45:46Z | 2018-10-03T16:45:46Z | 1994 | Mechanical Engineering | doi:10.15781/T2V11W50J | http://hdl.handle.net/2152/68663 | eng | 1994 International Solid Freeform Fabrication Symposium | Open | ['CAD/CAM', '3D digitized data', 'reverse engineering'] | Applications of 3D Laser Digitizing and Surfacing Technologies | Conference paper | https://repositories.lib.utexas.edu//bitstreams/9ad3ba3c-d02a-4c16-ae04-e78b0e77fd73/download | null | null | null | null | null | null | null | null |
['Mohammed, Mazher I.', 'Tatineni, Joseph', 'Cadd, Brenton', 'Peart, Greg', 'Gibson, Ian'] | 2021-10-28T21:43:23Z | 2021-10-28T21:43:23Z | 2016 | Mechanical Engineering | null | https://hdl.handle.net/2152/89708 | eng | 2016 International Solid Freeform Fabrication Symposium | Open | ['prosthesis', '3D printing', 'modelling', 'multi-material', 'soft tissue'] | Applications of 3D Topography Scanning and Multi-Material Additive Manufacturing for Facial Prosthesis Development and Production | Conference paper | https://repositories.lib.utexas.edu//bitstreams/e7c23dcc-8e62-4c68-9caf-737904a6565e/download | University of Texas at Austin | Prosthetic based rehabilitation offers several advantages over surgical intervention,
however, devices are generally handmade using labour intensive and subjective manufacturing
techniques. We investigate the use of optical scanning to capture the surface topography from
a volunteer’s facial anatomy, reconstruct this into a 3D CAD model, and from that design a
patient specific prosthesis. This approach offers many advantages over existing techniques as
data collection is non-intrusive, rapid and provides anatomically precise information. A CAD
approach affords greater flexibility when evaluating design iterations and allows for the
creation of ‘parts libraries’ for use with patients with no initial reference anatomy. The final
prosthesis is realised through high resolution, multi-material 3D printing for precise model
reproduction and to add functionalities such as mimicry of soft and hard tissues. Ultimately,
we believe our approach provides an optimised, low-cost approach for streamlining the
complete methodology for prosthesis production. | null | null | null | null | null | null |
['Liou, Frank', 'Slattery, Kevin', 'Kinsella, Mary', 'Newkirk, Joseph', 'Chou, Hsin-Nan', 'Landers, Robert'] | 2020-02-27T19:14:59Z | 2020-02-27T19:14:59Z | 2006 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/80092', 'http://dx.doi.org/10.26153/tsw/7113'] | eng | 2006 International Solid Freeform Fabrication Symposium | Open | Rapid Prototyping | Applications of a Hybrid Manufacturing Process for Fabrication and Repair of Metallic Structures | Conference paper | https://repositories.lib.utexas.edu//bitstreams/adef9ef7-1ac2-4e5b-926b-c9b17f714025/download | null | Since its appearance, rapid prototyping technology has been of interest to various industries that
are looking for a process to produce/build a part directly from a CAD model in a short time.
Among them, the direct metal deposition process is the only process which directly manufactures
a fully dense metal part without intermediate steps. However, challenges of the direct metal
deposition process include building overhang structures, producing precision surfaces, and
making parts with complex structures. Coupled between the additive and the subtractive
processes into a single workstation, the integrated process, or hybrid process, can produce a
metal part with machining accuracy and surface finish. Therefore, the hybrid process is
potentially a very competitive process to fabricate and repair metallic structures. This paper
summarizes the current development of the hybrid process to process high temperature metallic
materials, including tool steel and Ti64. Research in simulation and modeling, process
development, and actual part building and repair are discussed. | null | null | null | null | null | null |
['Isanaka, Sriram Praneeth', 'Liou, Frank'] | 2021-10-05T19:23:30Z | 2021-10-05T19:23:30Z | 2012 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88416', 'http://dx.doi.org/10.26153/tsw/15355'] | eng | 2012 International Solid Freeform Fabrication Symposium | Open | ['Cyber Enabled Manufacturing', 'additive manufacturing technology', 'cyber-physical systems'] | The Applications of Additive Manufacturing Technologies in Cyber-Enabled Manufacturing Systems | Conference paper | https://repositories.lib.utexas.edu//bitstreams/0cc996d3-09c5-422f-b222-c811d46fe2dc/download | University of Texas at Austin | The application of networked sensors and control in various areas, such as smart grids
and infrastructures, has become a recent trend, called cyber-physical systems. The Cyber
Enabled Manufacturing (CEM) environment is to apply these technologies in manufacturing
systems to handle a significantly greater magnitude of manufacturing data. Additive
manufacturing techniques print or place material layer by layer to form a part, thus have a great
potential to help accelerate CEM process by printing or embedding sensors and actuators in the
proper locations. This paper summarizes the roles of additive manufacturing technologies to help
establish a CEM environment. | null | null | null | null | null | null |
['Wohlert, Martin', 'Bourell, David L.', 'Das, Suman', 'Beaman, Joseph J.'] | 2019-09-23T15:19:57Z | 2019-09-23T15:19:57Z | 2000 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/75933', 'http://dx.doi.org/10.26153/tsw/3032'] | eng | 2000 International Solid Freeform Fabrication Symposium | Open | Densification | Applications of Powder Densification Maps to Direct Metal SLS/HIP Processing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/7a26921d-94f6-431e-9cad-8e900e9b5ba9/download | null | Recent investigations have shown that Direct Selective Laser Sintering in conjunction with Hot Isostatic Pressing (HIP) is capable of producing fully dense, near net shape, high performance metal components. A key aspect of this combined processing method is the selection of appropriate HIP process parameters to obtain full density parts. Powder Densification Maps
provide a powerful tool for predicting the effect of time, temperature, pressure, and material properties on part density. This paper summarizes developments in Powder Densification Map production for Ti-6Al-4V and Inconel 625 materials. A comparison of theoretically predicted and experimentally determined densities for a variety of processing conditions is presented. | null | null | null | null | null | null |
['Thomas, J.P.', 'Bender, B.A.', 'Pique, A.', 'Cooper, K.P.', 'Rayne, R.J.', 'Richardson, A.C.'] | 2019-10-18T17:07:55Z | 2019-10-18T17:07:55Z | 2001 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/76264', 'http://dx.doi.org/10.26153/tsw/3353'] | eng | 2001 International Solid Freeform Fabrication Symposium | Open | Fabrication | Applications of Solid Freeform Fabrication at the Naval Research Laboratory | Conference paper | https://repositories.lib.utexas.edu//bitstreams/efeacd08-1d4d-4e9f-b064-b1ae3ab37769/download | null | Solid Freeform Fabrication (SFF) and related techniques are used at the Naval Research
Laboratory (NRL) for a variety of materials related investigations. Research and applications
conducted over the past few years are described including: Helisys Laminated Object
Manufacturing System (LOMS) fabrication of: ceramic piezoelectric actuators, tooling for
multifunctional materials, and anatomical prototypes for surgical visualization; fabrication of
mesoscale electronic and sensor components using a laser forward transfer direct write
technique; and visualization of complex, 3-D microstructures using a Stratasys Fused-Deposition
Modeler. The paper closes with a brief overview of future SFF related work at the NRL. | Support for this work from DARPA, Office of Naval Research, and the Naval Research
Laboratory Core Research Program is gratefully acknowledged. | null | null | null | null | null |
['Joshi, M.S.', 'Flood, A.', 'Sparks, T.', 'Liou, F.W.'] | 2021-11-16T16:17:50Z | 2021-11-16T16:17:50Z | 2019 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90331', 'http://dx.doi.org/10.26153/tsw/17252'] | eng | 2019 International Solid Freeform Fabrication Symposium | Open | ['supervised learning algorithms', 'support vector machines', 'random forests', 'machine learning', 'additive manufacturing'] | Applications of Supervised Machine Learning Algorithms in Additive Manufacturing: A Review | Conference paper | https://repositories.lib.utexas.edu//bitstreams/a5e84fc3-f039-4f3d-8f2c-503624c84bdd/download | University of Texas at Austin | Additive Manufacturing (AM) simplifies the fabrication of complex geometries. Its scope
has rapidly expanded from the fabrication of pre-production visualization models to the
manufacturing of end use parts driving the need for better part quality assurance in the additively
manufactured parts. Machine learning (ML) is one of the promising techniques that can be used to
achieve this goal. Current research in this field includes the use of supervised and unsupervised
ML algorithms for quality control and prediction of mechanical properties of AM parts. This paper
explores the applications of supervised learning algorithms - Support Vector Machines and
Random Forests. Support vector machines provide high accuracy in classifying the data and is
used to decide whether the final parts have the desired properties. Random Forests consist of an
ensemble of decision trees capable of both classification and regression. This paper reviews the
implementation of both algorithms and analyzes the research carried out on their applications in
AM. | null | null | null | null | null | null |
['Wang, Jia-Chang', 'Dommati, Hitesh'] | 2021-11-08T23:06:34Z | 2021-11-08T23:06:34Z | 2017 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90071', 'http://dx.doi.org/10.26153/tsw/16992'] | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['slurry based stereolithography', 'high performance ceramics', 'non-self-supporting structures', 'earrings'] | Applied Solvent-Based Slurry Stereolithography Process to Fabricate High-Performance Ceramic Earrings with Exquisite Details | Conference paper | https://repositories.lib.utexas.edu//bitstreams/b0feaeeb-9f43-4a34-9880-c01327f0149b/download | University of Texas at Austin | This paper discusses the application of Slurry based Stereolithography additive
manufacturing process in the fabrication of complex earring models without any support structures
requirement, using High-Performance Ceramic (HPC) materials. The earring model chosen in this
study is a Rose flower with blossomed petals. The petals have edge thickness in microns and
extreme overhangs with a custom text and logo on the bottom. Using any other ceramic additive
manufacturing process, it requires support structures to build this model. The support removal in
such minute structures is not easy and not always successful. Using Solvent based Slurry
Stereolithography (3S) process, models with the micron details and overhangs can be easily built.
This is enabling the neat and clean post-processing procedure to maintain the exquisite details and
also gain high surface quality. The ceramic material used in this application is alumina. With some
additives, it will show in different colors like sapphire. The resultant flowers are vividly shown in
white, pink, green, and blue. In this study, it is also discussed about the slurry process,
Stereolithography system, and proven applications of the 3S process. | null | null | null | null | null | null |
['Emery, B.', 'Revier, D.L.', 'Lipton, J.I.'] | 2021-11-30T22:29:11Z | 2021-11-30T22:29:11Z | 2021 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90571', 'http://dx.doi.org/10.26153/tsw/17490'] | eng | 2021 International Solid Freeform Fabrication Symposium | Open | ['foams', 'viscous thread instability', 'viscous thread printing', 'cellular structures'] | Applied Viscous Thread Instability for Manufacturing 3D Printed Foams | Conference paper | https://repositories.lib.utexas.edu//bitstreams/68ca81b3-d9cc-45a1-98be-9ecaf4b86819/download | University of Texas at Austin | Traditional foams are fabricated via stochastic chemical processes that yield homogeneous
material properties. Foams can exhibit a wide range of material properties by varying process
controls allowing them to be used in many industrial and commercial applications. Previously,
additive manufacturing could only produce foam approximations in the form of traditional lattice
infill. Our work employs viscous thread printing (VTP) of thermoplastic polyurethane (TPU) on a
fused filament fabrication (FFF) printer, exploiting the semi-viscous nature of extruded filament
to coil producing a new type of printed foam. Specimens were tested under compression to
determine uniformity along principal axes and behavior under strain when compared to infill
patterns, such as grid and cubic. This work establishes that VTP as applied to TPU can be used to
manufacture programmable stiffness foams as a function of density, suited to a variety of needs
and should be considered as an alternative to traditional foams and other printed lattice geometries. | null | null | null | null | null | null |
['Chiu, Y. Y.', 'Chang, J. H.'] | 2020-02-17T14:30:03Z | 2020-02-17T14:30:03Z | 2004 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/79998', 'http://dx.doi.org/10.26153/tsw/7023'] | eng | 2004 International Solid Freeform Fabrication Symposium | Open | rapid prototyping | The Approach of Complex Insert Packaging Fabrication in Stereolithography | Conference paper | https://repositories.lib.utexas.edu//bitstreams/d7975c96-ac7d-43e9-bba2-e52ad356cffd/download | null | The approach of complex insert packaging fabrication in stereolithography is studied in the
paper. There are many difficulties being overcome, such as the dispensing shadowing problem
caused by the geometric shape of insert, the polymer feeding problem caused by greater insert
height than the layer thickness, and the positioning problem of insert that leads to instability of
packaging. These drawbacks led to unsatisfactory results of the insert packaging in
stereolithography. In order to solve the problems, a new method of complex inserts
packaging fabrication in stereolithography is proposed in this paper. Based on the geometric
information, function and assembly direction of the inserts, the packaging approach is developed.
The approach proposed in this paper has been verified by experiments. It brings considerable
contributions to the application of insert packaging in stereolithography. It is also favorable to
the improvement of insert packaging efficiency and assembly fabrication | null | null | null | null | null | null |
['Tarasova, A.', 'Wegner, A.', 'Witt, G.'] | 2021-11-18T02:19:44Z | 2021-11-18T02:19:44Z | 2019 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90412', 'http://dx.doi.org/10.26153/tsw/17333'] | eng | 2019 International Solid Freeform Fabrication Symposium | Open | ['maximum filler volume packing fraction', 'laser sintering', 'polymers', 'reinforcement', 'fillers', 'additive manufacturing'] | Approach to Defining the Maximum Filler Packing Volume Fraction in Laser Sintering on the Example of Aluminum-Filled Polyamide 12 | Conference paper | https://repositories.lib.utexas.edu//bitstreams/015c75c0-0de2-45a0-9561-a6e002ccde38/download | University of Texas at Austin | Laser sintering is one of the most popular additive manufacturing techniques that uses
thermoplastic polymer powders to generate layer-by-layer complex structures. Despite its broad
application, some limitations exist restricting its further development. One such restriction is a
narrow assortment of commercially available materials that would allow the production of the parts
with the desired mechanical characteristics, which is the case with the widely used Polyamide 12
(PA12). Reinforcement of a matrix polymer with metal particles is routinely performed to achieve
better mechanical properties. In this work, a PA12 system enhanced with a 35% volume ratio of
aluminum was investigated. Mechanical characteristics, e.g. elastic and flexural moduli, were
examined with respect to variation of manufacturing process parameters. In addition, a new
methodology was tested, which should help determine the maximum filler packing volume fraction
corresponding to the highest mechanical characteristics of a polymer-filler mixture. | null | null | null | null | null | null |
['Rivette, M.', 'Mognol, P.', 'Hascoet, JY.'] | 2020-03-05T18:51:28Z | 2020-03-05T18:51:28Z | 2006 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/80142', 'http://dx.doi.org/10.26153/tsw/7163'] | eng | 2006 International Solid Freeform Fabrication Symposium | Open | Rapid Prototyping | Approach Tolerance in the Assemblies of Evolutionary Hybrid Prototypes | Conference paper | https://repositories.lib.utexas.edu//bitstreams/7662fd9c-f37f-475c-b6e6-4a6f6da644ae/download | null | A new answer is proposed to replace the traditional “one shot” prototype (manufactured in
one piece with one process): the hybrid rapid prototype. It is used to highly reduce time,
cost and increase reactivity during the development times of new products.
The part is decomposed in several components which can quickly be changed and can be
manufactured with a process the most adapted.
The main objective of the presented method is to propose an available technological
assembly between the different components of the part in the respect of technological and
topological function, and initial tolerance.
Using a graph of representation, fuzzy logic and a tolerance point of view, some entities are
associated with a CIA (Assembly Identity Card) in accordance with evolutionary and
manufacturing analysis. This work will be illustrated by an industrial tooling for plastic
injection. | null | null | null | null | null | null |
['Dreifus, G.D.', 'Jin, Y.', 'Ally, N.', 'Post, B.K.'] | 2021-11-01T20:40:58Z | 2021-11-01T20:40:58Z | 2016 | Mechanical Engineering | null | https://hdl.handle.net/2152/89739 | eng | 2016 International Solid Freeform Fabrication Symposium | Open | ['geometric restrictions', 'big area additive manufacturing', 'fused deposition modeling', 'additive manufacture'] | Approaches to Geometric Data Analysis on Big Area Additively Manufactured (BAAM) Parts | Conference paper | https://repositories.lib.utexas.edu//bitstreams/916f64eb-e52a-45a9-aba3-3216012551c1/download | University of Texas at Austin | The promise of additive manufacturing is that a user can design and print complex geometries
that are very difficult, if not impossible, to machine. The capabilities of 3D printing are restricted
by a number of factors, including properties of the build material, time constraints, and
geometric design restrictions. In this paper, a thorough accounting and study of the geometric
restrictions that exist in the current iteration of additive manufacturing (AM) fused deposition
modeling (FDM) technologies on a large scale are discussed. Offline and online methodologies
for collecting data sets for qualitative analysis of large scale AM, in particular Oak Ridge
National Laboratory’s (ORNL) big area additive manufacturing (BAAM) system, are
summarized. In doing so, a survey of tools for designers and software developers is provided. In
particular, strategies in which geometric data can be used as training sets for smarter AM
technologies in the future are explained. | null | null | null | null | null | null |
['Lao, Wenxin', 'Li, Mingyang', 'Masia, Lorenzo', 'Tan, Ming Jen'] | 2021-11-08T22:34:42Z | 2021-11-08T22:34:42Z | 2017 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90058', 'http://dx.doi.org/10.26153/tsw/16979'] | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['rectangular extrudate', 'nozzle design', '3D printing for building and construction', 'extrusion based 3D printing'] | Approaching Rectangular Extrudate in 3D Printing for Building and Construction by Experimental Iteration of Nozzle Design | Conference paper | https://repositories.lib.utexas.edu//bitstreams/608f8abe-dd66-4683-b77a-ea49ef0abf48/download | University of Texas at Austin | In Extrusion based 3D Printing technology, the voids could be reduced and the surface finish of printed parts could be improved with extrudate shape optimization. For
large-scale 3D Printing technology like 3D Printing for Building and Construction, reducing printed layer height would increase the fabrication time drastically, while having
few effect on voids reduction and surface finish improvement. In this paper, an iterative
experimental approach to achieve the optimized nozzle design for rectangular shaped extrudate was proposed. Two nozzle prototypes were manufactured by Fused Deposition
Method and implemented for experimental tests, then a new nozzle design was created
based on the experimental extrudate shapes. This process iterated until a good rectangular extrudate shape was obtained. Printing tests were conducted with the optimized
nozzle, which showed the designed nozzle could help to eliminate the voids among the
printed parts and guarantee good surface finish without losing the speed of printing. | null | null | null | null | null | null |
['Mason, Michael S.', 'Huang, Tieshu', 'Landers, Robert G.', 'Leu, Ming C.', 'Hilmas, Gregory E.', 'Hayes, Michael W.'] | 2020-03-09T14:07:39Z | 2020-03-09T14:07:39Z | 9/4/07 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/80180', 'http://dx.doi.org/10.26153/tsw/7199'] | eng | 2007 International Solid Freeform Fabrication Symposium | Open | Aqueous-Based Extrusion Fabrication | Aqueous-Based Extrusion Fabrication of Ceramics on Demand | Conference paper | https://repositories.lib.utexas.edu//bitstreams/38bfdf1c-5680-4788-83a8-7442207e2589/download | null | Aqueous-Based Extrusion Fabrication is an additive manufacturing technique that
extrudes ceramic slurries of high solids loading layer by layer for part fabrication. The
material reservoir in a previously developed system has been modified to allow for
starting and stopping of the extrusion process on demand. Design pros and cons are
examined and a comparison between two material reservoir designs is made. Tests are
conducted to determine the optimal deposition parameters for starting and stopping the
extrudate on demand. The collected test data is used for the development of a deposition
strategy that improves material deposition consistency, including reduced material
buildup at sharp corners. Example parts are fabricated using the deposition strategy and
hardware design. | null | null | null | null | null | null |
['Delfs, P.', 'Schmid, H.-J.'] | 2021-11-08T22:37:43Z | 2021-11-08T22:37:43Z | 2017 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90059', 'http://dx.doi.org/10.26153/tsw/16980'] | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['process parameters', 'laser sintered parts', 'surface roughness', 'laser sintering'] | Areal Surface Characterization of Laser Sintered Parts for Various Process Parameters | Conference paper | https://repositories.lib.utexas.edu//bitstreams/9a57f82c-d39b-4fa7-a6bf-1fa556d56926/download | University of Texas at Austin | Laser sintered polymer parts consist of rough surfaces due to the layered manufacturing and adherence of
incomplete molten particles. The absolute roughness depend on various process parameters like build angle,
spatial position, build temperature, exposure order and layer time. Analyses with the help of several areal
roughness values of DIN EN ISO 25178-2 considering these parameters are introduced in this paper. Multiple
build jobs with 120 µm layer thickness and PA2200 powder were built on an EOS P396 machine using the same
build job design with varying process parameters. An individual sample part was designed to receive lots of
surface topography information with optical 3D measurements. The results show roughness dependencies for 0°
to 180° build angles in 15° steps and eleven distributed in-plane and three axial direction positions depending on
different build temperatures, reversed exposure order and layer times. Limitations of the varied parameters are
finally derived for the manufacturing of improved surface qualities. | null | null | null | null | null | null |
['Razdan, Anshuman', 'Henderson, Mark R.', 'Collins, Dan'] | 2019-02-19T20:28:07Z | 2019-02-19T20:28:07Z | 1998 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/73445', 'http://dx.doi.org/10.26153/tsw/597'] | eng | 1998 International Solid Freeform Fabrication Symposium | Open | ['PRISM', 'Anthropology'] | Art to Engineering: Pervasive RP activities at Arizona State University | Conference paper | https://repositories.lib.utexas.edu//bitstreams/dd3623a9-9a28-4363-9cc9-5e91b2b3913f/download | null | We present a sampling ofwidely diverse Rapid Prototyping activities at ASU. Through the interdisciplinary PRISM
project, RP is firmly involved in three areas: education, research and outreach. Two courses have been developed,
one teaches RP over the web and the other Visualization and RP as applied technologies aimed at interdisciplinary
graduates and seniors. Researchers and students from Engineering, Architecture and Industrial Design, Fine Arts
and Liberal Arts and Sciences and Business actively use RP. A recent formation ofthe PARfC (PRISM Advanced
Rapid-fabrication Consortium) Consortium with local industry will create a local and formal center for research,
education, service and training in Rapid Fabrication. | null | null | null | null | null | null |
['Stavroulakis, P.', 'Davies, O.', 'Tzimiropoulos, G.', 'Leach, R.K.'] | 2021-11-09T14:54:28Z | 2021-11-09T14:54:28Z | 2018 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90087', 'http://dx.doi.org/10.26153/tsw/17008'] | eng | 2018 International Solid Freeform Fabrication Symposium | Open | ['artificial intelligence', 'data fusion', 'photogrammetry', 'fringe projection', 'deflectometry', 'segmentation network'] | Artificial Intelligence-Enhanced Mutli-Material Form Measurement for Additive Materials | Conference paper | https://repositories.lib.utexas.edu//bitstreams/6efe19f6-3225-4e23-9852-1405e9892be6/download | University of Texas at Austin | The range of materials used in additive manufacturing (AM) is ever growing nowadays.
This puts pressure on post-process optical non-contact form measurement systems as different
system architectures work most effectively with different types of materials and surface finishes.
In this work, a data-driven artificial intelligence (AI) approach is used to recognise the material of
a measured object and to fuse the measurements taken from three optical form measurement
techniques to improve system performance compared to using each technique individually. More
specifically, we present a form measurement system which uses AI and machine vision to enable
the efficient combination of fringe projection, photogrammetry and deflectometry. The system has
a target maximum permissible error of 50 μm and the prototype demonstrates the ability to measure
complex geometries of AM objects, with a maximum size of (10 × 10 × 10) cm, with minimal user
input. | null | null | null | null | null | null |
Gibson, I. | 2021-10-05T15:46:10Z | 2021-10-05T15:46:10Z | 2012 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88396', 'http://dx.doi.org/10.26153/tsw/15335'] | eng | 2012 International Solid Freeform Fabrication Symposium | Open | ['Additive Manufacturing', 'Rapid Prototyping'] | Ask Not What Additive Manufacturing Can Do For You... | Conference paper | https://repositories.lib.utexas.edu//bitstreams/b319e394-28bb-4251-b449-faf06b176d02/download | University of Texas at Austin | The paraphrase of John F Kennedy’s famous words is for 2 purposes. Firstly it is to
acknowledge that there are some people who have considered that it is a major part of their life’s
work to promote Additive Manufacturing (AM) technology as primarily a selfless act. AM
comprises an outstanding range of technology that should be brought to public attention as a true
revolution in how we design and manufacture products. The second purpose is to show that
technology development is only one part of this promotion process and that there are other ways
in which we can get involved.
This paper describes the author’s journey over the (approximately) 20 years since he was
introduced to what was then called Rapid Prototyping (RP). It is not a catalogue of research and
development projects but rather a list of activities that he has been involved in to help promote
and support AM technology over these years. It will describe the conferences, activities,
associations and publications that have been created to allow academics and professionals to
describe and discuss their work amongst themselves and to the larger society. | null | null | null | null | null | null |
['Deng, Dongping', 'Chen, Yong'] | 2021-10-07T17:32:07Z | 2021-10-07T17:32:07Z | 2013 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88489', 'http://dx.doi.org/10.26153/tsw/15423'] | eng | 2013 International Solid Freeform Fabrication Symposium | Open | ['additive manufacturing', 'in-situ assembly', 'thin-shell structure', 'origami design', 'folding', 'fabrication speed'] | Assembled Additive Manufacturing – A Hybrid Fabrication Process Inspired by Origami Design | Conference paper | https://repositories.lib.utexas.edu//bitstreams/507c9518-c8e8-4060-a218-539ca9cd8c03/download | University of Texas at Austin | Inspired by the recent developments on origami structures, we investigated a fast AM process for
fabricating prototype models of thin-shell shapes. By combining the origami design and the additive
manufacturing technology, a new fabrication process named Assembled Additive Manufacturing (AAM)
is developed. In the process, a digital model is first analyzed to determine geometries that are fabricated
by the layer-based and origami-based approaches. The thin shell model for the origami-based approach is
then unfolded into a foldable 2D sheet. After the fabrication and folding of the 2D sheet, a postprocessing
process is developed before the final prototype is fabricated using the layer-based fabrication process.
Algorithms of analyzing and unfolding polygonal model and the details of the process are introduced in
the paper; design parameters, mechanics analysis and test cases are also discussed. | null | null | null | null | null | null |
['Telenko, Cassandra', 'Seepersad, Carolyn Conner'] | 2021-09-30T14:37:38Z | 2021-09-30T14:37:38Z | 2010 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88258', 'http://dx.doi.org/10.26153/tsw/15199'] | eng | 2010 International Solid Freeform Fabrication Symposium | Open | ['Selective Laser Sintering', 'Rapid Manufacturing', 'life-cycle', 'nylon powder material', 'material properties', 'environmental effects'] | Assessing Energy Requirements and Material Flows of Selective Laser Sintering of Nylon Parts | Conference paper | https://repositories.lib.utexas.edu//bitstreams/f6bc4c52-736c-42ff-8033-fbbc2aeab1af/download | University of Texas at Austin | Selective laser sintering (SLS) is a prominent technology for rapid manufacturing (RM) of
functional parts. SLS and competitive RM technologies are generally assumed to be more
environmentally sustainable than conventional manufacturing methods because the additive
process minimizes tooling, material waste, and chemical fluids. A thorough life cycle analysis
(LCA) of the environmental impacts of SLS has yet to be published. This study focuses on a
section of the SLS part life-cycle. It tracks the nylon powder material flows from the extraction
and synthesis of the material to SLS part production. Basic material properties and
environmental effects are reported. Estimates of material waste and energy use are also reported
and compared with those of injection molding. | null | null | null | null | null | null |
['Cloots, M.', 'Spierings, A.B.', 'Wegener, K.'] | 2021-10-11T21:45:39Z | 2021-10-11T21:45:39Z | 8/16/13 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88654', 'http://dx.doi.org/10.26153/tsw/15588'] | eng | 2013 International Solid Freeform Fabrication Symposium | Open | ['selective laser melting', 'SLM', 'metal parts', 'support structures', 'overhanging surfaces', 'support minimization', 'process heat', 'geometrical distortions', 'additive manufacturing'] | Assessing New Support Minimizing Strategies for the Additive Manufacturing Technology SLM | Conference paper | https://repositories.lib.utexas.edu//bitstreams/67b73d0a-7b05-4b89-87c7-cc7d2f9f6e15/download | University of Texas at Austin | To successfully produce metal parts by SLM, additional support structures are needed to
support overhanging surfaces in order to dissipate process heat and to minimize geometrical
distortions induced by internal stresses. These structures are often massive and require additional
post-processing time for their removal. A minimization of the extent to which support structures
are needed would therefore significantly reduce manufacturing and finishing efforts and costs. A
specific component segmentation strategy is developed. It allows the segmentation of critical
areas of the component by applying a specific scanning strategy with appropriate energy input
and optimized supporting strategies. The results indicate that the supporting effort can generally
be reduced, e.g. overhang geometries with an angle to the horizontal of less than 35° can be
manufactured without any support. The successful realization of the segmentation strategy in
combination with optimized support structures allows the implementation of a stacking strategy,
thereby using the available work space more efficiently. | null | null | null | null | null | null |
['Poudel, Arun', 'Yasin, Mohammad Salman', 'Shao, Shuai', 'Shamsaei, Nima'] | 2023-02-10T14:23:05Z | 2023-02-10T14:23:05Z | 2022 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/117453', 'http://dx.doi.org/10.26153/tsw/44334'] | eng | 2022 International Solid Freeform Fabrication Symposium | Open | ['Laser powder bed fusion (L-PBF)', 'Non-destructive testing', 'X-ray computed tomography', 'Process window', 'Rockwell hardness'] | Assessing the Feasibility of Process Window Estimation for L-PBF Ti-6Al-4V through Hardness Measurements | Conference paper | https://repositories.lib.utexas.edu//bitstreams/7764f1b3-b6c3-4f12-a73d-85e1049cde9a/download | null | Optimizing the process window for an additively manufactured material using X-ray
computed tomography (XCT) is a time-, labor-, and capital-intensive process where a large number
of coupons need to be analyzed in the process parameter space. Hence, as a cheaper and faster
alternative, this study assessed the relationship between relative density and hardness of laser
powder bed fused (L-PBF) Ti-6Al-4V. Coupons with different levels of porosity were fabricated
by changing the recommended laser power in the range of ±20% in an interval of 10%. The
martensitic microstructure didn’t vary significantly with the change in laser power. On the other
hand, Rockwell C hardness (HRC) did. HRC was observed to be in good correlation with the defect
content in the coupons. Higher defect content in the coupons resulted in lower HRC and vice versa.
Hence, the hardness measurement technique can be used to estimate the process window of L-PBF
Ti-6Al-4V. | null | null | null | null | null | null |
['Kletetzka, I.', 'Neitzel, F.', 'Schmid, H.-J.'] | 2024-03-25T22:31:21Z | 2024-03-25T22:31:21Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124323', 'https://doi.org/10.26153/tsw/50931'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['laser sintering', 'powder', 'ceramic', 'additive manufacturing'] | Assessing the Impact of the Powder Production Method on Ceramic-filled Polyamide Composites made by Laser Sintering | Conference paper | https://repositories.lib.utexas.edu//bitstreams/4b2f310c-35c4-4afe-bcb7-8fa7f5e63515/download | University of Texas at Austin | Polymer composites represent the industry standard in injection molding for the production
of plastic components with increased requirements in terms of heat resistance and stiffness. In the
field of laser sintering (LS), these materials are less common so far. In order to extend the available
material variety for the LS process, new ceramic-filled Polyamide 613 powders are investigated
within the scope of this work. Here, the resulting properties from two different powder production
methods are compared. One filled powder is produced by dry blending and the other powder with
the same filler and filling ratio is produced by encapsulating the filler particles inside the polymer
particles within the dissolution-precipitation process. It was found that encapsulating the filler
particles can provide certain benefits for the processability, for example an improved powder
flowability or better filler dispersion. However, encapsulating the filler also alters the thermal
properties of the precipitated powder. | null | null | null | null | null | null |
['Hauser, C.', 'Childs, T.H.C.', 'Dalgarno, K.W.', 'Eane, R.B.'] | 2019-03-12T17:54:01Z | 2019-03-12T17:54:01Z | 1999 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/73605', 'http://dx.doi.org/10.26153/tsw/747'] | eng | 1999 International Solid Freeform Fabrication Symposium | Open | ['Metallography', 'Atmosphere'] | Atmospheric Control during Direct Selective Laser Sintering of Stainless Steel 314S Powder | Conference paper | https://repositories.lib.utexas.edu//bitstreams/dabd68c4-c148-4594-8e64-fb48c74d4917/download | null | Stainless steel grade 314S powders have been Selective Laser Sintered (SLS) in three
different argon/air (oxygen) atmospheric mixtures. The amount of oxygen present during the
heating, melting and fusing of the metal powder strongly limits the range of laser powers and
scanning speeds for successful processing. As oxygen levels diminish, powder oxidation
reduces. This reduces absorption of laser energy as well as balling and other detrimental
surface phenomena. This paper reports the conditions for creating sintered layers and
observations of part quality variation within these conditions. Sintered microstructure
observations are also helpful in determining thermal history changes. | null | null | null | null | null | null |
Koch | 2018-05-03T18:25:19Z | 2018-05-03T18:25:19Z | 1993 | Mechanical Engineering | doi:10.15781/T2ZC7SB82 | http://hdl.handle.net/2152/65053 | eng | 1993 International Solid Freeform Fabrication Symposium | Open | ['DIGIBOT 3D', 'laser digitizer', '3D systems', 'CAD', 'CAM', 'CAE'] | Automated 4 Axis Adaptive Scanning with the Digibotics Laser Digitizer | Conference paper | https://repositories.lib.utexas.edu//bitstreams/ecadda3e-47bd-4e2a-b7f4-7160840e6fb6/download | null | The DIGIBOT 3D Laser Digitizer is a high performance 3D input device which
combines laser ranging technology, personal computing, and Microsoft Windows in an
attractive desktop package.
With its full four-axis scanning capabilities, the DIGIBOT provides a simple,
accurate, and quick way to copy or inspect complex, sculpted surfaces. The DIGIBOT
provides an effective solution for many industrial and academic problems involving 3D
design, inspection, replication, analysis, and visualization/animation. By measuring
sequential points and producing a standard list of x/y/z coordinates, the DIGIBOT
interfaces to any CAD/CAM/CAE imaging or animation software that reads 3D points,
contours, or triangular facets. | null | null | null | null | null | null |
['Zhao, Xiyue', 'Imandoust, Aidin', 'Khanzadeh, Mojtaba', 'Imani, Farhad', 'Bian, Linkan'] | 2021-12-01T22:39:34Z | 2021-12-01T22:39:34Z | 2021 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90642', 'http://dx.doi.org/10.26153/tsw/17561'] | eng | 2021 International Solid Freeform Fabrication Symposium | Open | ['anomaly detection', 'melt pool monitoring', 'sparse representation', 'unsupervised learning', 'direct energy deposition', 'additive manufacturing'] | Automated Anomaly Detection of Laser-Based Additive Manufacturing Using Melt Pool Sparse Representation and Unsupervised Learning | Conference paper | https://repositories.lib.utexas.edu//bitstreams/fa2422df-92ff-4ec2-83e7-65a0e2b11b56/download | University of Texas at Austin | Advanced thermal imaging is increasingly invested in direct energy deposition (DED) additive
manufacturing (AM) to cope with information visibility of melt pool and tackle process
inconsistency. However, there are key challenges regarding the feasibility of current image-guided
monitoring methodologies in the DED process. First, high-resolution thermal images consist of
millions of pixels captured by hundreds of frames lead to the curse of dimensionality in analysis.
Second, the presence of various exogenous noise, ill-structured data, and significant cluster
imbalance limit the capability of the current methodologies to perform real-time monitoring. The
objective of this research is to advance the frontier of melt pool monitoring in DED process by
designing an automated and unsupervised anomaly detection on high-dimensional thermal image
data. Specifically, we develop a variational autoencoder to generate a low-dimensional
representation of each input thermal image data. A Gaussian mixture model and K-Mean clustering
are integrated with the generative model to split latent space into homogenous regions and detect
anomalies. Experimental results show that the proposed methodology is highly effective in
detecting defective melt pools with accuracy up to 94.52% and a false alarm rate of less than 2.1%. | null | null | null | null | null | null |
['Khoshnevis, B.', 'Kwon, H.', 'Bukkapatnam, S.'] | 2019-10-18T16:37:59Z | 2019-10-18T16:37:59Z | 2001 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/76255', 'http://dx.doi.org/10.26153/tsw/3344'] | eng | 2001 International Solid Freeform Fabrication Symposium | Open | Contour | Automated Construction using Contour Crafting | Conference paper | https://repositories.lib.utexas.edu//bitstreams/e21a2cda-7539-4e0c-884d-f0c2a14ea52e/download | null | This paper presents some concepts and initial investigation of a novel construction
automation approach using the Contour Crafting (CC) layered fabrication process, developed at
the University of Southern California. CC uses computer control to take advantage of the
superior surface forming capability of trowels, used by craftsmen and builders since ancient
times, to create large intricate structures with smooth and accurate surfaces. The potential of CC
became evident from the initial investigations and experiments with various materials and
geometries. Using this process, a single house or a colony of houses, each with possibly a
different design, may be automatically constructed in a single setup. | null | null | null | null | null | null |
['Ramin, E.', 'Harris, R. A.'] | 2020-03-10T14:49:22Z | 2020-03-10T14:49:22Z | 2007 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/80211', 'http://dx.doi.org/10.26153/tsw/7230'] | eng | 2007 International Solid Freeform Fabrication Symposium | Open | Tissue Engineering scaffolds | Automated Design of Tissue Engineering Scaffolds by Advanced CAD | Conference paper | https://repositories.lib.utexas.edu//bitstreams/5fdae97c-8581-4cf8-a8b4-adb524e91907/download | null | The design of scaffolds with an intricate and controlled internal structure represents a
challenge for Tissue Engineering. Several scaffold manufacturing techniques allow the
creation of complex and random architectures, but have little or no control over geometrical
parameters such as pore size, shape and interconnectivity- things that are essential for tissue
regeneration. The combined use of CAD software and layer manufacturing techniques allow
a high degree of control over those parameters, resulting in reproducible geometrical
architectures. However, the design of the complex and intricate network of channels that are
required in conventional CAD, is extremely time consuming: manually setting thousands of
different geometrical parameters may require several days in which to design the individual
scaffold structures. This research proposes an automated design methodology in order to
overcome those limitations. The combined use of Object Oriented Programming and
advanced CAD software, allows the rapid generation of thousands of different geometrical
elements. Each has a different set of parameters that can be changed by the software, either
randomly or according to a given mathematical formula, so that they match the different
distribution of geometrical elements such as pore size and pore interconnectivity.
This work describes a methodology that has been used to design five cubic scaffolds with
pore size ranging from about 200 to 800 µm, each with an increased complexity of the
internal geometry. | null | null | null | null | null | null |
['Cooper, A.G.', 'Kang, S.', 'Kietzman, J.W.', 'Prinz, F.B.', 'Lombardi, J.L.', 'Weiss, L.'] | 2019-03-01T17:39:48Z | 2019-03-01T17:39:48Z | 1998 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/73519', 'http://dx.doi.org/10.26153/tsw/669'] | eng | 1998 International Solid Freeform Fabrication Symposium | Open | ['Mold Shape Deposition', 'Ceramic materials'] | Automated Fabrication of Complex Molded Parts Using Mold SOM | Conference paper | https://repositories.lib.utexas.edu//bitstreams/b6223daa-1c38-47d3-a09f-ef0fc87d8ff9/download | null | Mold Shape Deposition Manufacturing (Mold SDM) is a Solid Freeform Fabrication
technique for producing complex shaped fugitive wax molds. A vari~ty of castable. polymer and
ceramic materials have been used to make parts from these molds. ThIS paper descnbes the Mold
SDM method and an automated mold building machine based on a commercial CNC mill. Process
steps, material selection and equipment issues are explained. Alumina, silicon nitride, polyurethane
and epoxy parts with feature sizes ranging from 0.5 to 30 mm will be shown, as well as preassembled mechanisms and multi-material parts. | null | null | null | null | null | null |
['Klosterman, Don', 'Chartoff, Richard', 'Osborne, Nora', 'Graves, George'] | 2018-12-06T21:30:53Z | 2018-12-06T21:30:53Z | 1997 | Mechanical Engineering | doi:10.15781/T2SX64W60 | http://hdl.handle.net/2152/71432 | eng | 1997 International Solid Freeform Fabrication Symposium | Open | ['LOM', 'CMC'] | Automated Fabrication of Monolithic and Ceramic Matrix Composites via Laminated Object Manufacturing (LaM) | Conference paper | https://repositories.lib.utexas.edu//bitstreams/2d02a74e-fe28-45b7-a8a2-ff86af5265ed/download | null | This report summarizes recent developments in a research program for fabricating
advanced monolithic and ceramic matrix composite parts using Laminated Object
Manufacturing (LOM). Both silicon carbide (SiC) and SiC/SiC composites are
discussed. The LOM process is used to produce green forms that are then densified using
various post processing operations. The monolithic ceramic LOM process was advanced
through the implementation of an automated solvent spray bonding step, significant
improvement in decubing with new software, and an intensive round ofmechanical
characterization. The LOM process for making CMC green forms is fully developed.
This entailed implementing a process for making suitable SiC fiber preforms, a laser
cutting capability, a decubing strategy, and a binder resin cure procedure. Further
research is ongoing for the post processing pyrolysis and reaction bonding steps as
discussed herein. | null | null | null | null | null | null |
['Steidle, Cheri', 'Klosterman, Don', 'Osborne, Nora', 'Graves, George', 'Chartoff, Richard'] | 2019-02-27T17:45:00Z | 2019-02-27T17:45:00Z | 1998 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/73508', 'http://dx.doi.org/10.26153/tsw/658'] | eng | 1998 International Solid Freeform Fabrication Symposium | Open | ['Chemical Engineering', 'LOM'] | Automated Fabrication of Nonresorbable Bone Implants Using Laminated Object Manufacturing (LOM) | Conference paper | https://repositories.lib.utexas.edu//bitstreams/a85b69a2-e075-429e-bf3e-1865b83501cc/download | null | null | null | null | null | null | null | null |
['Mathewson, Brian B.', 'Newman, Wyatt S.', 'Heuer, Arthur H.', 'Cawley, James D.'] | 2018-11-02T14:59:11Z | 2018-11-02T14:59:11Z | 1995 | Mechanical Engineering | doi:10.15781/T2959CT1S | http://hdl.handle.net/2152/69332 | eng | 1995 International Solid Freeform Fabrication Symposium | Open | ['CAD', 'custom manufacturing', '3D Laminated Engineering Components'] | Automated Fabrication ofCeramic Components from Tape-Cast Ceramic | Conference paper | https://repositories.lib.utexas.edu//bitstreams/5be81cf5-85df-485e-bdb4-27b78ddc6aa9/download | null | This paper describes a machine and process for automated fabrication of functional 3-D
laminated engineering components, ceramics in the present example. A laser cuts successive layers
of a part derived from a CAD model description out of unfired tape-cast ceramic sheets
vacuum-clamped to an x-y sled. A material-handling robot uses a selective-area gripper to extract
only the desired part outlines from the surrounding waste material, then stacks the slices to build the
part. This system design enables rapid manufacture of functional engineering components with
arbitrarily complex internal and external geometries from virtually any material available in sheet
form. | null | null | null | null | null | null |
['Dakshnamoorthy, Vignesh', 'Taylor, Robert V.'] | 2021-11-01T21:19:33Z | 2021-11-01T21:19:33Z | 2016 | Mechanical Engineering | null | https://hdl.handle.net/2152/89757 | eng | 2016 International Solid Freeform Fabrication Symposium | Open | ['lattice structure', 'optimization', 'hinge fitting', 'goose neck door hinge', 'part design', 'stiffness', 'additive manufacturing'] | Automated Lattice Optimization of Hinge Fitting with Displacement Constraint | Conference paper | https://repositories.lib.utexas.edu//bitstreams/47d45fcc-d6dc-466c-a26b-98de52fb3e0c/download | University of Texas at Austin | Additive manufacturing enables fabrication of complex lattice cell structures that are not
manufacturable using conventional methods. In order to exploit this lattice capability in
structural designs, the effect on structural performance must be considered. This paper uses a
goose neck door hinge component to illustrate the effects of lattice structure optimization when
stiffness criteria drive part design. The effect of intermediate lattice cell density parameters on
resulting lattice configurations from automated lattice structure optimization are studied and it is
found that the compliance of the model depends upon the range of intermediate density elements
present. The paper then compares the effect of a displacement constraint on optimized weight
from rib-stiffened and lattice-stiffened shell models. It is shown that optimized weight results
from the lattice configuration depend on part stiffness requirements. The results show that lattice
structures can be successfully implemented in weight-critical components where relaxation in the
displacement constraint is acceptable. | null | null | null | null | null | null |
['Chang, Y. C.', 'Pinilla, J. M.', 'Kao, J.H.', 'Dong, J.', 'Ramaswami, K.', 'Prinz, F.B.'] | 2019-03-11T16:45:53Z | 2019-03-11T16:45:53Z | 1999 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/73582', 'http://dx.doi.org/10.26153/tsw/724'] | eng | 1999 International Solid Freeform Fabrication Symposium | Open | ['SFF', 'CAD'] | Automated Layer Decomposition for Additive/Subtractive Solid Freeform Fabrication | Conference paper | https://repositories.lib.utexas.edu//bitstreams/35b09cd4-ffc4-4e0c-94b4-0c6cbc82d722/download | null | The new additive/subtractiye technology (Shape. Deposition Manufacturing) enhances Solid Freeform
Fabrication (SFF) capability inproducing near net-shape surface finish. This. technology also builds parts in fewer
layers compared with conventional layered manufacturing technology. However, to decompose a part into freeform
layers usually requires expensive geometric computation.. Also, to plan build. sequences often requires human
intervention because ofthe complicated spatial relationships among the freeform layers. At present decomposition and
build sequence planning are both performed by experienced designers/users. In this paper, a novel decomposition
approach based on surface splitting is proposed to facilitate .computation and planning of the additive/subtractive SFF
processes. The results shown in this paper are from models with 3D planar geometry. Continuous effort is devoted
into extending and implementing this new approach for models with 3Dfreeform.geometry | null | null | null | null | null | null |
['Wadidie, A.', 'Studer, G. M.', 'Villez, K.'] | 2024-03-27T03:18:46Z | 2024-03-27T03:18:46Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124461', 'https://doi.org/10.26153/tsw/51069'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['large area additive manufacturing', '3D printing', 'thresholding', 'edge detection'] | Automated layer identification in large area additive manufacturing (LAAM): A comparison of image thresholding and edge detection techniques | Conference paper | https://repositories.lib.utexas.edu//bitstreams/5981225d-ea2c-444f-9d76-bcc44c622817/download | University of Texas at Austin | Our study aims to develop an automated method for identifying layers on images of 3Dprinted walls from a LAAM printer, as manual identification is subjective and can be timeconsuming. We applied three different image processing methods to identify edges between layers:
simple thresholding, Otsu thresholding, and Canny edge detection. Otsu thresholding was found
to be the most accurate and required minimal manual intervention. From our study, we propose a
new approach by going through essential steps for greater accuracy. This research demonstrates
the feasibility of using computer-based methods to automatically identify layers in 3D printing,
reducing manual time and effort and improving the strength and quality of 3D-printed parts. | null | null | null | null | null | null |
['Rasoolian, Behnam', 'Pegues, Jonathan', 'Shamsaei, Nima', 'Silva, Daniel'] | 2021-11-30T20:22:53Z | 2021-11-30T20:22:53Z | 2019 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90535', 'http://dx.doi.org/10.26153/tsw/17454'] | eng | 2019 International Solid Freeform Fabrication Symposium | Open | ['additive manufacturing', 'fatigue behavior', 'roughness', 'radius of curvature'] | An Automated Method for Geometrical Surface Characterization for Fatigue Analysis of Additive Manufactured Parts | Conference paper | https://repositories.lib.utexas.edu//bitstreams/c63b0cb0-a249-48fa-bcb7-ed65d7280e50/download | University of Texas at Austin | Recent interest to implement additive manufactured parts into structural applications has created
a critical need to better understand the fatigue behavior of these parts. Alloys such as Ti-6Al-4V
are popular in the aerospace and biomedical industries due to their superior strength to weight ratio
and biocompatibility. Previous works have associated fatigue behavior with surface roughness,
especially radius of curvature of notches. It is therefore important to develop a fast, reliable and
consistent methodology for extracting such curvatures. The contribution of this paper is in
providing an automated method for extracting radius of curvature using image processing
techniques and optimization. Results on fatigue life prediction indicates similar results between
the automated method and manually extracted radii in a significantly shorter period of time. | null | null | null | null | null | null |
['Borish, Michael', 'Roschli, Alex'] | 2023-01-26T14:51:21Z | 2023-01-26T14:51:21Z | 2022 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/117311', 'http://dx.doi.org/10.26153/tsw/44192'] | eng | 2022 International Solid Freeform Fabrication Symposium | Open | ['slicing', 'Additive manufacturing', 'wire coextrusion', 'wire embedding', 'self-heating molds', 'composite'] | Automated Path Planning for Wire Feeding in Large Format Polymer Additive Manufacturing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/eabf70cf-d5ed-40a4-9720-215ee4a304ba/download | null | Polymer-based large format industrial additive manufacturing (AM) technology continues to expand
into new application areas. One area of interest is large scale composite molds and dies. These molds and dies
can be used for out-of-autoclave tooling applications. However, at these sizes, several challenges remain that
prevent the use of AM technology due to cost. One such challenge is the need to heat these molds in large
thermal ovens. To address this challenge, researchers at Oak Ridge National Laboratory developed the
necessary hardware to allow co-extruded wire to be embedded into the material during construction. Using this
hardware, a demonstration mold was successfully constructed and subjected to mechanical testing. The
construction of this object required a unique pathing solution to achieve success. In this paper, we describe the
needed software development in ORNL Slicer 2.0 to allow the automated production of this unique pathing
solution. | null | null | null | null | null | null |
['Dong, Jianpeng', 'Kao, Ju-Hsien', 'Pinilla, Jose M.', 'Chang, Yu-Chi', 'Prinz, Fritz B.'] | 2019-03-11T16:47:56Z | 2019-03-11T16:47:56Z | 1999 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/73583', 'http://dx.doi.org/10.26153/tsw/725'] | eng | 1999 International Solid Freeform Fabrication Symposium | Open | ['CAD', 'CAM'] | Automated Planning for Material Shaping Operations in Additive/Subtractive Solid Freeform Fabrication | Conference paper | https://repositories.lib.utexas.edu//bitstreams/f19fb637-eb29-4c87-8867-017897ac6dd2/download | null | Combining the advantages of layered manufacturing and material removal
processes, additive/subtractive solid freeform fabrication (A/S SFF) can build parts with
complex shapes without compromising precision requirements. However, preparing
material removal operations requires special expertise, which has in fact become one of the
bottlenecks of the A/S SFF manufacturing process. To achieve automated planning, a
shaping process planner is being developed based on. 3D solid representation and a surface
classification scheme. This planner can generate numeric control (NC) codes for CNC
milling in an automatic fashion on non-undercut features of arbitrary 3D input geometry.
Planning approaches are also presentedinorde~to>shape parts accurately and efficiently.
The proposed shaping planner thus delivers on the promise offully automated process
planning in A/S SFF. | null | null | null | null | null | null |
['Bohn, John Helge', 'Wozny, Michael J.'] | 2018-04-19T16:20:26Z | 2018-04-19T16:20:26Z | 1992 | Mechanical Engineering | doi:10.15781/T2QJ78F8R | http://hdl.handle.net/2152/64380 | eng | 1992 International Solid Freeform Fabrication Symposium | Open | ['CAD-models', 'de facto', 'CAD-models'] | Automatic CAD-model Repair: Shell-Closure | Conference paper | https://repositories.lib.utexas.edu//bitstreams/8f26990e-8520-43f0-a295-e23658000bfe/download | null | Shell-closure is critical to the repair of CAD-models described in the .STL file-format,
the de facto solid freeform fabrication industry-standard. Polyhedral CAD-models that
do not exhibit shell-closure, i.e. have cracks, holes, or gaps, do not constitute valid solids
and frequently cause problems during fabrication. This paper describes a solution for
achieving shell-closure of polyhedral CAD-models. The solution accommodates nonmanifold
conditions, and guarantees orientable shells. There are several topologically
ambiguous situations that might arise during the shell-closure process, and the solution
applies intuitively pleasing heuristics in these cases. | null | null | null | null | null | null |
['Mireles, Jorge', 'Terrazas, Cesar', 'Medina, Francisco', 'Wicker, Ryan'] | 2021-10-11T22:09:27Z | 2021-10-11T22:09:27Z | 8/16/13 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88663', 'http://dx.doi.org/10.26153/tsw/15597'] | eng | 2013 International Solid Freeform Fabrication Symposium | Open | ['Arcam A2 Electron Beam Melting', 'Electron Beam Melting', 'automatic feedback control', 'temperature stabilization', 'infrared camera'] | Automatic Feedback Control in Electron Beam Melting Using Infrared Thermography | Conference paper | https://repositories.lib.utexas.edu//bitstreams/9ccafcc0-24f5-4390-ad23-ceb4d77f518c/download | University of Texas at Austin | An infrared (IR) camera has been installed in an Arcam A2 Electron Beam
Melting (EBM) system for improved layer-by-layer monitoring and feedback control of
the EBM build process. Previous work has demonstrated the temperature variations
possible during a build (e.g., part/powder bed temperature elevates as build height
increases) that have been shown to produce microstructural changes as well as a range of
defects that can be detected (e.g., temperature anomalies and porosity). A stabilization of
temperature during a build can lead to more uniform microstructure and mechanical
properties throughout the fabricated part. Further, full spatial and temporal control of
temperature could lead to controlled microstructural architectures in EBM-fabricated
parts. An automatic feedback control system was developed to acquire a temperature
matrix of the current layer and used as an input to a ‘ghost operator’ that modifies the
necessary parameters (speed function, beam current, melt cycle’s post-heating time) for
temperature stabilization to minimize microstructural variations. | null | null | null | null | null | null |
['Cook, D.', 'Knier, B.', 'Gervasi, V.', 'Stahl, D.'] | 2021-09-30T19:56:45Z | 2021-09-30T19:56:45Z | 2010 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88289', 'http://dx.doi.org/10.26153/tsw/15230'] | eng | 2010 International Solid Freeform Fabrication Symposium | Open | ['solid-freeform-fabrication', 'finite-element analysis', 'minimal-mass lattice structures', 'structural performance', 'process parameters', 'multi-functional structures', 'high-performance-computing'] | Automatic Generation of Strong, Light, Multi-Functional Structures from FEA Output | Conference paper | https://repositories.lib.utexas.edu//bitstreams/4563c28d-e4c0-44d1-8b63-2295b6c46382/download | University of Texas at Austin | An automated process is being developed that will generate a minimal-mass lattice structure that
is fabrication-ready for a selected solid-freeform-fabrication (SFF) process. The results of a
standard, structural, finite-element analysis (FEA) are processed to define the selection,
alignment and sizing of unit lattice elements, such that a minimal-mass structure can be defined.
This process will allow for considerations of structural performance (e.g. safety factor), multiple
loads, as well as process parameters (e.g. materials and min./max. sizes). Further development
would lead to the definitions of composites and multi-functionality, as well as high-performance-computing (HPC) capabilities. | null | null | null | null | null | null |
['Ridwan, S.', 'Mireles, J.', 'Gaytan, S.M.', 'Espalin, D.', 'Wicker, R.B.'] | 2021-10-12T22:31:50Z | 2021-10-12T22:31:50Z | 2014 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88756', 'http://dx.doi.org/10.26153/tsw/15690'] | eng | 2014 International Solid Freeform Fabrication Symposium | Open | ['layerwise monitoring', 'spatial monitoring', 'infrared camera', 'electron beam melting', 'infrared thermography', 'thermal data', 'geometric data'] | Automatic Layerwise Acquisition of Thermal and Geometric Data of the Electron Beam Melting Process using Infrared Thermography | Conference paper | https://repositories.lib.utexas.edu//bitstreams/133f5c95-d166-4694-8727-fd1232af5af1/download | University of Texas at Austin | Layerwise monitoring has become an area of interest in the field of additive
manufacturing because of potential to further enable part qualification during every stage of
fabrication. Spatial monitoring and qualification during part fabrication has never before been
possible with traditional manufacturing processes such as milling or casting. An IR camera has
been externally annexed atop an EBM system to obtain layerwise thermographs throughout the
fabrication process. This paper demonstrates a process to compare each layer of fabrication using
automatically acquired thermal images to the corresponding CAD file for each fabricated object.
Two different methods of image analysis for part detection were compared (analysis on the basis
of color and analysis by edge detection). Detection allowed the quantification of processing
information (average temperature and surface anomalies) and geometric information (surface
area and perimeter). A percent error of the compared surface area was found to range from 5%-
17%, and automatically acquired temperature measurements were within 7.8K of the recorded
thermograph. The methods presented in this research showcase the beginning steps of integrated
metrology in advanced manufacturing systems and automatic monitoring of per-part thermal
behavior and part quality. | null | null | null | null | null | null |
['Thomas, Charles L.', 'Hayworth, Kenneth J.'] | 2018-11-14T17:23:11Z | 2018-11-14T17:23:11Z | 1996 | Mechanical Engineering | doi:10.15781/T2C82508X | http://hdl.handle.net/2152/70245 | eng | 1996 International Solid Freeform Fabrication Symposium | Open | ['3D object', 'thermoplastic droplet deposition process', '3D aliasing'] | Automating Sheet-Based Fabrication: The Conveyed-Adherent Process | Conference paper | https://repositories.lib.utexas.edu//bitstreams/94788f8e-f1ae-4892-9e06-add8ab41e84e/download | null | A new automated fabrication technology is described which breaks the fabrication process into spatially separate
layer-formation and layer-bonding stages. The technique uses sheet material on a substrate as feedstock and cuts
cross-section contours into the material before conveying the material on the substrate to a stacking station.
Advantages include (a) speed, (b) versatility in fabrication materials, and (c) ability to fabricate hollows, embed or
cast secondary materials, and selectively enhance or degrade material properties on a regional basis.
A prototype fabricator has been built which automates all aspects ofthis process except weeding. Applications
demonstrated using this machine include traditional rapid prototyping and visualization-model creation as well as
functional machines taking advantage of embedding and cast-in-place techniques. | null | null | null | null | null | null |
['Stroble, J. K.', 'Landers, R. G.', 'Liou, F. W.'] | 2020-03-05T18:55:53Z | 2020-03-05T18:55:53Z | 9/14/06 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/80143', 'http://dx.doi.org/10.26153/tsw/7164'] | eng | 2006 International Solid Freeform Fabrication Symposium | Open | Laser Aided Manufacturing Process | Automation of a Hybrid Manufacturing System Through Tight Integration of Software and Sensor Feedback | Conference paper | https://repositories.lib.utexas.edu//bitstreams/ab004900-e7bf-4a6b-81f7-cab9563988d9/download | null | This paper presents a framework for the automation of the Laser Aided Manufacturing Process
(LAMP) lab at the University of Missouri-Rolla. The groundwork for the proposed system
involves the integration of the LabVIEW software package and a PXI-8195 real time controller
with several sensors and actuators. The incorporation of all key control parameters into one
virtual instrument will help achieve the goal of an automated hybrid system. To achieve this
goal, a five-phase plan, which will be further discussed in the paper, has been developed. The
first phase of this plan, which includes the deposition of a thin walled structure without DNC
communication between LabVIEW and the CNC has been achieved, and will be the focus of this
paper | null | null | null | null | null | null |
['Ye, Jiafeng', 'Yasin, Mohammad Salman', 'Muhammad, Muztahid', 'Liu, Jia', 'Vinel, Aleksandr', 'Slvia, Daniel', 'Shamsaei, Nima', 'Shao, Shuai'] | 2021-12-01T22:18:09Z | 2021-12-01T22:18:09Z | 2021 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90636', 'http://dx.doi.org/10.26153/tsw/17555'] | eng | 2021 International Solid Freeform Fabrication Symposium | Open | ['nitinol', 'laser beam-powder bed fusion', 'process parameters', 'Bayesian optimization'] | Bayesian Process Optimization for Additively Manufactured Nitinol | Conference paper | https://repositories.lib.utexas.edu//bitstreams/dba1a8f6-d315-4aa0-88c3-40882cba161e/download | University of Texas at Austin | Additively manufactured nitinol enables the design and rapid prototyping of the shape
memory alloy with great flexibility and cost-effectiveness in various applications. To achieve high-density fabrication of nitinol, we utilize a Gaussian process-based Bayesian optimization method
to efficiently optimize process parameters of the laser beam-powder bed fusion (LB-PBF) process
in this work. Specifically, Gaussian process regression is applied to formulate a surrogate model
between the critical process parameters (i.e., laser power, scanning speed) and the residual porosity
of the nitinol samples. Then Bayesian optimization is integrated to successively explore the design
space to search for the optimal process parameters. These two methods are integrated to find the
global optimum iteratively. Compared with the traditional trial-and-error methods, the proposed
method can quickly find the optimal process parameter for the high-quality nitinol samples,
especially with many process parameters, and accelerate the innovations with nitinol in additive
manufacturing. | null | null | null | null | null | null |
['Maskery, I.', 'Aremu, A.O.', 'Simonelli, M.', 'Tuck, C.', 'Wildman, R.D.', 'Ashcroft, I.A.', 'Hague, R.J.M.'] | 2021-10-13T20:45:58Z | 2021-10-13T20:45:58Z | 2014 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88782', 'http://dx.doi.org/10.26153/tsw/15716'] | eng | 2014 International Solid Freeform Fabrication Symposium | Open | ['selective laser melting', 'lattice', 'aluminum alloy'] | The BCC Unit Cell for Latticed SLM Parts; Mechanical Properties as a Function of Cell Size | Conference paper | https://repositories.lib.utexas.edu//bitstreams/750511b9-39f2-48b7-b80c-5f45fe862d18/download | University of Texas at Austin | The existing framework describing the mechanical properties of lattices places strong
emphasis on one important property, the relative density of the repeating cells. In
this work, we explore the effects of cell size, attempting to construct more complete
models for the performance of lattices. This was achieved by examining the elastic
modulus and ultimate tensile strength of latticed parts with a range of unit cell sizes
and fixed density. The parts were produced by selective laser melting (SLM). The
examined cell type was body-centred-cubic (BCC), a cell of high relevance for SLM
because of its self-supporting structure. We obtained power law relationships for the
mechanical properties of our latticed specimens as a function of cell size, which are
similar in form to the existing laws for the density dependence. These can be used
to predict the properties of latticed column structures comprised of BCC cells, and
may be easily amended for other situations. In addition, we propose a novel way to
analyse the elastic modulus data, which may lead to more general models, applicable
to parts of varying size. Lastly, our general methodology may be of use in future
studies which explore the other parameters that determine lattice performance; the
choice of cell type, the global shape of the lattice structure and the type of stress. | null | null | null | null | null | null |
['Ramirez-Chavez, Irving E.', 'Lee, Christine', 'Bhate, Dhruv'] | 2023-02-24T14:45:29Z | 2023-02-24T14:45:29Z | 2022 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/117524', 'http://dx.doi.org/10.26153/tsw/44404'] | eng | 2022 International Solid Freeform Fabrication Symposium | Open | ['Additive Manufacturing', 'beam deletion', 'cellular materials', 'densification strain', 'maximum transmitted stress', 'perturbation', 'energy absorption'] | Beam Deletion in Square Honeycombs for Improved Energy Absorption Under Quasi-Static In-Plane Compression | Conference paper | https://repositories.lib.utexas.edu//bitstreams/c6d4caf4-d501-4750-839f-541dd5f30763/download | null | When selecting cellular materials for energy absorption applications, there have
traditionally been two choices: a periodic structure such as a honeycomb, or a stochastic one, as
seen in foams. Both choices involve a global definition governing the allocation of the members
of the structure, be they beams or surfaces. With Additive Manufacturing, the exploration of more
complex structures enables the creation of aperiodicity through the local modification of periodic
structures. This paper explores one application of this approach by deleting beams in square
honeycombs, with the aim of avoiding localization of failure that generates significant undulations
in the stress plateau under in-plane quasi-static compression. These perturbed structures show
improved energy absorption behavior by generating higher Specific Energy Absorption for a given
transmitted stress and relative density than their periodic counterparts. This work thus argues for
further exploration of localized aperiodicity as an approach to finely tune energy absorption
performance. | null | null | null | null | null | null |
['Li, Yongqiang', 'Chen, Yong'] | 2021-09-30T20:00:56Z | 2021-09-30T20:00:56Z | 9/23/10 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88290', 'http://dx.doi.org/10.26153/tsw/15231'] | eng | 2010 International Solid Freeform Fabrication Symposium | Open | ['topology optimization', 'principal stress line', 'beam structures', 'minimum compliance'] | Beam Structure Optimization for Additive Manufacturing based on Principal Stress Lines | Conference paper | https://repositories.lib.utexas.edu//bitstreams/8d06615f-9061-4db0-add4-682c5ae4adbb/download | University of Texas at Austin | The benefits of component design with cellular structures have been demonstrated in a wide
variety of applications. The recent advances in additive manufacturing and high performance computing
have enabled us to design a product component with adaptive cellular structures to achieve significantly
better performance. However, designing a product component with such structures, especially its shape
and topology, poses significant challenges. Many approaches in topology optimization have been
developed before for the purpose. In this paper, we present a novel structural optimization method based
on the principal stress line analysis of a continuum domain. We first present the theoretical basis of our
optimization method. We then discuss the properties of principal stress lines and their computation in a
given design domain. Accordingly a novel structural optimization method is presented including size,
shape and topology optimization. Related mathematical formulations and algorithms are also given for
generating a beam structure with the minimum compliance. Three test cases are presented to illustrate
the presented method. | null | null | null | null | null | null |
['Johnson, W.M.', 'Rowell, M.', 'Deason, B.', 'Eubanks, M.'] | 2021-10-04T21:18:43Z | 2021-10-04T21:18:43Z | 2011 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88349', 'http://dx.doi.org/10.26153/tsw/15288'] | eng | 2011 International Solid Freeform Fabrication Symposium | Open | ['Additive Manufacaturing', 'benchmarking models', 'open source AM system', 'fused deposition modeling'] | Benchmarking Evaluation of an Open Source Fused Deposition Modeling Additive Manufacturing System | Conference paper | https://repositories.lib.utexas.edu//bitstreams/860a3433-80c5-49c1-9fe4-77299d93babf/download | University of Texas at Austin | The availability of more affordable open source Additive Manufacturing (AM) systems has lead
to the increased awareness and use of AM technologies. However, further expansion will
necessitate improved reliability and an increased understanding in the limitations of these
systems. This paper will review previous benchmarking models, and present the development of
a new benchmarking model and its application in the evaluation of an open source AM system
based on fused deposition modeling (FDM). The proposed benchmarking model includes
various geometric features to evaluate the AM system in terms of dimensional accuracy, thermal
warpage, staircase effect, and geometric and dimensional tolerances. | null | null | null | null | null | null |
['Yasa, E.', 'Demir, F.', 'Akbulut, G.', 'Cızıoğlu, N.', 'Pilatin, S.'] | 2021-10-12T22:42:40Z | 2021-10-12T22:42:40Z | 2014 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88760', 'http://dx.doi.org/10.26153/tsw/15694'] | eng | 2014 International Solid Freeform Fabrication Symposium | Open | ['powder-bed metal fusion', 'additive manufacturing', 'Inconel 625', 'AM machine'] | Benchmarking of Different Powder-Bed Metal Fusion Processes for Machine Selection in Additive Manufacturing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/d85c45bf-72dc-4bb1-93c4-49556fca37c3/download | null | In the last decade, additive manufacturing has gained significant interest for direct part
production and started to change the way companies manufacture products; even in very
demanding sectors like aerospace. The biggest challenge for a wider industrial acceptance still
stands as the need for more reliable, repeatable and precise machines for additive manufacturing.
This paper presents a comprehensive benchmarking study for the selection of an additive
manufacturing machine for powder-bed metal fusion process, i.e. Selective Laser Melting or
Direct Metal Laser Sintering or Laser Cusing. Four different machine vendors for the same
technology to be employed for aeroengine part manufacturing using Inconel 625 powder have
been involved for comparing different machine specifications. Many aspects such as dimensional
accuracy, surface quality, need of support structures, density, hardness and process limits
(minimum wall thickness, overhang surfaces, inclinations and curvatures, etc.) are addressed in
the paper. The state-of-the-art in machines for powder-bed metal fusion process is presented
aiming at understanding the current limitations of the technology available today. | null | null | null | null | null | null |
['Jayaram, Dureen', 'Bagchi, Amit', 'Jara-Almonte, C.C.', 'Oreilly, Sean'] | 2018-09-27T19:48:41Z | 2018-09-27T19:48:41Z | 1994 | Mechanical Engineering | doi:10.15781/T2BG2HV81 | http://hdl.handle.net/2152/68608 | eng | 1994 International Solid Freeform Fabrication Symposium | Open | ['Rapid prototyping', 'SLS', 'LOM'] | Benchmarking of Rapid Prototyping Systems - Beginning to Set Standards | Conference paper | https://repositories.lib.utexas.edu//bitstreams/c427b662-4f55-4313-8d08-9289cf87eee6/download | null | Many rapid prototyping (RP) technologies are available today and more are being developed
around the world. The absence of benchmarking standards in the RP industry has led
manufacturers to use their own standards and make claims about superior performance. The need
for testing standards is already felt; standardization will become imperative in the near future. The
present work aims to lay the groundwork for the development of standards to measure various
performance factors. Issues such as appearance and finish are studied qualitatively; the test part
and some findings are presented. Issues such as repeatability, warpage, curl, creep, shrinkage and
tensile strength are proposed to be studied quantitatively; test parts designed for studying these are
described. Benchmarking standards will help users choose proper systems for their applications
and help operators in monitoring machine performance, enabling better control over part building. | null | null | null | null | null | null |
['Al Nabhani, Dawood', 'Kassab, Ali', 'Habbal, Osama', 'Mohanty, Pravansu', 'Ayoub, Georges', 'Pannier, Christopher'] | 2024-03-25T22:04:26Z | 2024-03-25T22:04:26Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124311', 'https://doi.org/10.26153/tsw/50919'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['additive manufacturing', 'recycling', 'PLA', '2023 Solid Freeform Fabrication Symposium'] | Benchmarking the Tensile Properties of Polylactic Acid (PLA) Recycled Through Fused Granule Fabrication Additive Manufacturing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/fc18f980-2e7a-4365-a034-a4c28a2df445/download | University of Texas at Austin | To progress toward a circular economy of thermoplastic polymers, the adoption of 3D
printers to make functional articles can facilitate distributed recycling. To this end, the
mechanical degradation of polymers through multiple recycling cycles must be quantified. This
work presents a procedure and benchmark dataset of tensile property degradation for polylactic
acid (PLA) feedstock in multiple recycling passes with a fused granule fabrication process. To
establish recycling with minimal processing (shredding and sieving), modifications were
required to the granule feeding hopper of the 3D printer. Two distinct orientations were chosen
to obtain tensile test coupons. These coupons were die-cut from machined 3D printed rectangular
cross-section tubes, with one orientation along the bead (0°) and the other perpendicular to it
(90°). Tensile properties are presented for 3D printed virgin material and one, two, three, and
four passes of recycling. In terms of print orientation, the results indicate that samples pulled at
0° and 90° exhibited similar mechanical properties. However, there was an average decrease of
3.1% in ultimate tensile strength and a 1.7% decrease in elastic modulus for the samples along
90° orientation for all recycling passes. The samples along 0° demonstrated a 13.7% higher
strain at fracture compared to those along 90°. Regarding the number of recycling passes, the
findings suggest that the mechanical characteristics of PLA remain largely unaffected even after
undergoing four recycling cycles. However, when the material is pulled in the direction of the
bead, a 3.09% decrease in ultimate tensile strength is observed in the fourth recycling pass. The
elastic modulus and strain at fracture did not exhibit a clear trend. It is important to note that the
testing results display some variability, which can be attributed to a combination of stochasticity
in the printing process and the preparation procedure employed. | null | null | null | null | null | null |
Walczyk, Daniel F. | 2019-02-19T19:36:41Z | 2019-02-19T19:36:41Z | 1998 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/73435', 'http://dx.doi.org/10.26153/tsw/587'] | eng | 1998 International Solid Freeform Fabrication Symposium | Open | ['RP methods', 'steel laminations'] | Bevel Cutting Methods and Cutting Trajectory Control for Steel Laminations Used in Tooling | Conference paper | https://repositories.lib.utexas.edu//bitstreams/270a95fa-92c0-4da3-95da-2293556ce1b2/download | null | Bevel cutting of steel laminations used in profiled-edge laminated tooling allows for a more accurate
representation of the intended die surface, since stair-stepping at the edges is eliminated. Based on experiments
involving maximum cutting speed, bevel angle and kerf quality, the three recommended methods for bevel cutting
steel are (best to worst) pulsed Nd:YAG laser with hard-optic delivery, abrasive water jet, and machining with the
flute edge of an endmill. For each method, bevel angles of up to 80 degrees are possible. Further experimentation
was used to determine the optimal process parameters for kerf quality, with constant cutting speed being one ofthe
main requirements. Finally, a new techIlique to assure constant velocity along the entire lamination cutting trajectory
is developed. | null | null | null | null | null | null |
['Nassar, A.R.', 'Reutzel, E.W.'] | 2021-10-19T19:10:06Z | 2021-10-19T19:10:06Z | 2015 | Mechanical Engineering | null | https://hdl.handle.net/2152/89326 | eng | 2014 International Solid Freeform Fabrication Symposium | Open | ['directed energy deposition', 'layer-by-layer manufacturing', 'additive manufacturing', 'overhangs', 'Ti-6Al-4V'] | Beyond Laser-by-Laser Additive Manufacturing - Voxel-Wise Directed Energy Deposition | Conference paper | https://repositories.lib.utexas.edu//bitstreams/15de08ed-f4e7-4206-a0ab-fb7722377a68/download | University of Texas at Austin | Conventional additive manufacturing is a layer-by-layer process, reliant on the sequential
deposition of 2-1/2 D layers oriented along a build axis. During directed energy deposition a feedstock is directed into a continuous melt pool formed by a laser or electron beam. The ability to
produce overhangs is limited due to the gravitational, surface tensions, and fluid-flow force acting
on unsupported melt pools. Here, we present a novel, directed-energy-deposition technique where
vertical and overhanging structures are formed by laser power modulation and the motion of a
laser beam in three dimensional space along the build-up direction, rather than strictly in a single
layer. We demonstrate that highly-overhanging Ti-6Al-4V structure, i.e. in which the overhang
angle exceeds 45 degrees with respect to the x-y plane, can be deposited using the developed
technique. High-speed imaging is used to gain insight into the physics of the process. The use of
a pulsed or power-modulated beam is found to be critical to the formation of overhangs. | null | null | null | null | null | null |
['Post, Brian K.', 'Richardson, Bradley', 'Lind, Randall', 'Love, Lonnie J.', 'Lloyd, Peter', 'Kune, Vlastimil', 'Rhyne, Breanna J.', 'Roschli, Alex', 'Hannan, Jim', 'Nolet, Steve', 'Veloso, Kevin', 'Kurup, Parthiv', 'Remo, Timothy', 'Jenne, Dale'] | 2021-11-08T21:14:09Z | 2021-11-08T21:14:09Z | 2017 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90043', 'http://dx.doi.org/10.26153/tsw/16964'] | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['big area additive manufacturing', 'wind turbine molds', 'wind turbine', 'tooling'] | Big Area Additive Manufacturing Application in Wind Turbine Molds | Conference paper | https://repositories.lib.utexas.edu//bitstreams/4bd41921-cad5-4749-b193-587b24dccb3a/download | University of Texas at Austin | Tooling is a primary target for current additive manufacturing (AM), or 3D printing,
technology because of its rapid prototyping capabilities. Molds of many sizes and shapes have
been produced for a variety of industries. However, large tooling remained out of reach until the
development of large-scale composite AM manufacturing processes like the Big Area Additive
Manufacturing (BAAM) system. The Department of Energy’s Oak Ridge National Laboratory
(ORNL) worked with TPI Composites to use the BAAM system to fabricate a wind turbine blade
mold. The fabricated wind turbine blade mold was produced in 16 additively manufactured
sections, was 13 meters long, had heating channels integrated into the design, and was mounted
into a steel frame post fabrication. This research effort serves as a case study to examine the
technological impacts of AM on wind turbine blade tooling and evaluate the efficacy of this
approach in utility scale wind turbine manufacturing. | null | null | null | null | null | null |
['Liggett, J.C.', 'Snelling, D.A.', 'Xu, M.', 'Myers, O.J.', 'Thompson, S.M.'] | 2021-12-06T21:37:22Z | 2021-12-06T21:37:22Z | 2021 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90680', 'http://dx.doi.org/10.26153/tsw/17599'] | eng | 2021 International Solid Freeform Fabrication Symposium | Open | ['high chromium white iron', 'bimetallic castings', 'wear performance', 'lattice structures', 'metal additive manufacturing', '316L'] | Bimetallic Castings for Wear Performance through Infiltration of Additive Manufactured Metal Lattice Structures | Conference paper | https://repositories.lib.utexas.edu//bitstreams/6ee9c895-d990-4a67-9e51-1d969aa6aef6/download | University of Texas at Austin | High chromium white iron is an alloy frequently employed in the production of abrasion
resistive wear components. Ground engaging components for mining or earthmoving frequently
require such materials, as well as slurry pumps for mining applications. Although high chromium
white iron alloy demonstrates excellent wear performance due to the formation of chromium
carbides, it is brittle and lacks toughness. Impact resistance is often of great importance for ground
engaging wear components; hence, this study will investigate a method by which high chromium
white iron wear components may be reinforced by the formation of a bimetallic composite. In this
research, an additively manufactured lattice structure of 316L stainless steel is infiltrated with high
chromium white iron via the metal casting process. This procedure results in a bimetallic casting
of reinforced white iron. Complete infiltration and metallurgical diffusion bonding were observed
between the two alloys, validating this method as a means of reinforcing high chromium white
iron castings for applications requiring high abrasion and impact resistance. | null | null | null | null | null | null |
['Chakravarthy, Kumaran M.', 'Bourell, David L.'] | 2021-09-30T18:28:16Z | 2021-09-30T18:28:16Z | 2010 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88271', 'http://dx.doi.org/10.26153/tsw/15212'] | eng | 2010 International Solid Freeform Fabrication Symposium | Open | ['binder system', 'non metallics', 'bipolar plates', 'SLS', 'graphite-phenolic parts'] | Binder Development for Indirect SLS of Non Metallics | Conference paper | https://repositories.lib.utexas.edu//bitstreams/4e7647de-d636-44fa-8263-3e7abd675c1e/download | University of Texas at Austin | In this work, a binder system for non metallics such as graphite has been developed and
tested. A graphite-phenolic mixture was used for making bipolar plates using SLS.
Phenolic resin melts (~90°C) instead of cross-linking (~165°C) in the SLS machine.
During post processing in a furnace, the SLS parts slumped due to remelting of phenolic
resin with no other binder present to hold the powder together. To prevent this slumping
and to increase the green strength of the SLS parts, a new binder system was developed
with Nylon/11 added. Nylon/11 has a melting point of ~185°C and is able to hold the
SLS part together until the phenolic can cross link, preventing slumping. Single layer
scan experiments with different compositions and SLS parameters were run to identify
optimum composition and SLS parameters. Three point bend specimens were prepared
with 70 wt. % Graphite-25 wt. % Phenolic- 5 wt. % Nylon/11 and 70 wt. % Graphite-20
wt. % Phenolic- 10 wt. % Nylon/11, tested and compared to graphite-phenolic parts. No
significant increase in green strength was attained with Nylon/11 addition. | null | null | null | null | null | null |
['Volpp, J.', 'Zhang, W.', 'Abbott, W.', 'Coban, A.', 'McConnell, S.', 'Marola, S.', 'Casati, R.', 'Padamati, R.', 'Lupoi, R.'] | 2024-03-25T23:26:43Z | 2024-03-25T23:26:43Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124335', 'https://doi.org/10.26153/tsw/50943'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['powder sheet processing', 'laser materials processing', 'vaporization', 'spatter', 'additive manufacturing'] | Binder evaporation during powder sheet Additive Manufacturing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/64aab548-a645-4f43-b0c4-49de6ce95ab3/download | University of Texas at Austin | Several Additive Manufacturing methods are well established and found access into regular production in
multiple sectors. For processing metals, typically wire or powder is used as feedstock. Wire processing is typically
used for comparably large structure building, while powder processes offer, in general, a more precise metal
application. For Powder Bed Fusion processes, very fine powder is used (typical 20 µm to 65 µm), while for
Directed Energy Deposition powders are in the range between 50 µm and 160 µm. Such fine powders can be a
health risk for humans (aspiration, skin integration). Avoiding contact with the powders in a production
environment can be a big effort or not avoidable. Therefore, an alternative process was developed that provides
the powder not as free powder particles but in form of powder sheets. For enabling the necessary bonding between
the particles, a binder is used. In order to understand the impact of the binder during laser processing of the powder
sheets, single pulse and line treatments were produced and recorded with high-speed imaging. Recordings show
the vaporization of the binder and the related ejections of powder particles. At lower energy input, the binder
evaporation led to less spattering, which indicates that a binder heating at low heating rates induces less pressure
on the powder particles. | null | null | null | null | null | null |
['Pekin, Senol', 'Zangvil, Avigdor', 'Ellingson, William'] | 2019-03-01T17:21:42Z | 2019-03-01T17:21:42Z | 1998 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/73512', 'http://dx.doi.org/10.26153/tsw/662'] | eng | 1998 International Solid Freeform Fabrication Symposium | Open | ['FDC', 'EVA-wax'] | Binder Formulation in EVA-wax system for Fused Deposition of Ceramics | Conference paper | https://repositories.lib.utexas.edu//bitstreams/732d6614-bf6b-46de-84ea-0359e2b6c5ac/download | null | Blends in the ethylene vinyl acetate (EVA) - wax system have been evaluated as potential
binders.to be used in fused deposition of ceramics (FDC). In order to obtain good handling
strength, it was indicated that the melting point of the polymer needs to be lower than that of the
wax. In this context, it was shown that the melting point of the EVA decreases as the vinyl
acetate content in the copolymer increases. By measuring the viscosity as a macroscopic
property, it was shown that 20 % vinyl acetate-containing EVA is miscible in microcrystalline
wax up to, atleast, 30 %.Binders used in FDC need to have low viscosity and it was pointed out
that the slumping can be one main problem associated with binders with low viscosity. Thus,
thermolysis of wax at low temperature is suggested as a solution. The volumetric thermal
expansion and melt strength of an EVA-wax blend were displayed as a function of temperature,
in the form of a penetration test. | null | null | null | null | null | null |
['Agarwal, Kuldeep', 'Vangapally, Sairam', 'Sheldon, Alexander'] | 2021-11-04T21:05:01Z | 2021-11-04T21:05:01Z | 2017 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90028', 'http://dx.doi.org/10.26153/16949'] | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['binder jet additive manufacturing', 'binder jetting', 'biocomposite', 'tricalcium phosphate', 'stainless steel', 'bone scaffolds', 'implants'] | Binder Jet Additive Manufacturing of Stainless Steel - Tricalcium Phosphate Biocomposite for Bone Scaffold and Implant Applications | Conference paper | https://repositories.lib.utexas.edu//bitstreams/c309633c-bad0-4473-aaad-d2304737a420/download | University of Texas at Austin | Scaffolds are 3D biocompatible structures that mimic the extracellular matrix properties
(mechanical support, cellular activity and protein production) of bones and provide place for cell
attachment and bone tissue formation. Their performance depends on chemistry, pore size, pore
volume, and mechanical strength. Recently, additive manufacturing (AM) has been used as a
means to produce these scaffolds. This paper explores a new biocomposite manufactured using
Binder Jet AM process. Stainless steel and tricalcium phosphate are combined to form a composite
and used in different volume fractions to produce parts with varying densities. Layer thickness,
sintering time and sintering temperature are varied to study the effect of process parameters on the
microstructure, dimensions and mechanical properties of the resulting structure. It is found that the
resulting biocomposite can be tailored by varying the process to change its properties and mimic
the properties of scaffolds in bone tissue applications. | null | null | null | null | null | null |
['Rishmawi, I.', 'Salarian, M.', 'Vlasea, M.'] | 2021-11-09T14:48:28Z | 2021-11-09T14:48:28Z | 2018 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90085', 'http://dx.doi.org/10.26153/tsw/17006'] | eng | 2018 International Solid Freeform Fabrication Symposium | Open | ['binder jetting', 'additive manufacturing', 'irregular iron powder', 'sintering schedule', 'part density'] | Binder Jetting Additive Manufacturing of Water-Atomized Iron | Conference paper | https://repositories.lib.utexas.edu//bitstreams/3255ea8e-1696-4572-9ebb-80403c82a6f7/download | University of Texas at Austin | Binder jetting additive manufacturing (BJAM) was deployed to processing of low-cost, water-atomized
pure iron powder. Surface morphology and particle size distribution of the powder were fully characterized
using scanning electron microscopy (SEM) and particle dynamic image analysis via Retsch Camsizer X2.
Cylindrical samples were fabricated, and in the AM process, the effects of powder compaction, layer
thickness and liquid binder level on green part density were studied. Density analysis was performed
using x-ray computed tomography (µCT). The potential application and future research work will be
outlined based on the characterization results. | null | null | null | null | null | null |
['Caballero, K.', 'Medrano, V.A.', 'Arrieta, E.', 'Sandoval, H.', 'Wicker, R. B.', 'Medina, F.'] | 2023-04-03T17:42:08Z | 2023-04-03T17:42:08Z | 2022 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/117727', 'http://dx.doi.org/10.26153/tsw/44606'] | eng | 2022 International Solid Freeform Fabrication Symposium | Open | ['Metal Additive Manufacturing', 'Binder Jetting', 'Sintering', 'Simufact Additive', 'Shrinkage'] | Binder Jetting of 316L process simulation tools evaluation | Conference paper | https://repositories.lib.utexas.edu//bitstreams/99336320-019f-4849-9e81-14de881adc90/download | null | Binder Jetting has become one of the most popular Additive Manufacturing technologies
over the years due to its low cost and fast production times, nevertheless this technology has a
steep learning curve due to the shrinkage induced to parts during sintering. Since shrinkage is not
uniform along the part, it’s hard to efficiently determine what areas will be distorted hence this
needs to be taken into consideration when designing a new part and many iterations need to be
printed until dimensional accuracy is achieved, as a result production time and cost significantly
increase. New Binder Jetting simulation tools are being developed and tested; this software will
help the technology be more robust and user-friendly for the industry. The software computes a
sintering simulation and can provide displacement results making support positioning more
efficient, in addition, newer versions of the software can export a compensated model which will
be able to be sintered without supports. To evaluate the simulation software, a dimensional test
artifact model was designed and printed, then compared with the software predicted model
simulation results. The simulation software was used in an initial evaluation of the test artifact
geometry to identify areas of concern in the model and document them so efficiency when
predicting material behavior during the sintering process can be evaluated. In addition, an
evaluation of the effects of different sintering process parameters on the physical and mechanical
properties of the material will be analyzed considering the inert sintering atmosphere of the
process. Finally, printing parameters of the machine such as layer thickness, binder saturation, and
recoat speed among others will also be evaluated. | null | null | null | null | null | null |
['Diaz-Moreno, Carlos A.', 'Rodarte, C.', 'Ambriz, S.', 'Bermudez, D.', 'Roberson, D.', 'Terrazas, C.', 'Espalin, D.', 'Ferguson, R.', 'Shafirovich, E.', 'Lin, Y.', 'Wicker, Ryan B.'] | 2021-11-09T14:46:32Z | 2021-11-09T14:46:32Z | 2018 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90084', 'http://dx.doi.org/10.26153/tsw/17005'] | eng | 2018 International Solid Freeform Fabrication Symposium | Open | ['ceramics', 'aluminum nitride', '3D components fabrication', 'thermal conductivity', 'binder jetting', 'additive manufacturing'] | Binder Jetting of High Temperature and Thermally Conductive (Aluminum Nitride) Ceramic | Conference paper | https://repositories.lib.utexas.edu//bitstreams/a7960e4c-eca7-48e4-a4f7-1da3b5a46351/download | University of Texas at Austin | This work reports on the novel fabrication of aluminum nitride (AlN) complex components using
binder jetting, on the use of sintering and hot isostatic pressing (HIPing) to increase their density,
and on the characterization of the printed material, including thermal conductivity. The HIPing
parameters employed were a temperature of 1900 °C using a rich nitrogen atmosphere at a
pressure of 30,000 psi during 8 h. Results show that the printed and HIPed AlN components had
a 1.96 g/cm3 (60.12%) density when compared to theoretical values. The thermal conductivity
for densified and HIPed components was measured in the range from 23 °C to 500 °C resulting
in values from 4.82 W/m*K to 3.17 W/m*K, respectively. Characterization using scanning
electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction was used to
investigate the ceramic structural morphology of the sintered and HIPed material, its chemical
composition, and crystal structure of the binder jetting manufactured AlN components. | null | null | null | null | null | null |
['Ruprecht, John', 'Agarwal, Kuldeep', 'Ahmed, Shaheen'] | 2021-11-16T16:05:12Z | 2021-11-16T16:05:12Z | 2019 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90326', 'http://dx.doi.org/10.26153/tsw/17247'] | eng | 2019 International Solid Freeform Fabrication Symposium | Open | ['binder saturation', 'layer thickness', 'drying time', 'dimensional tolerance', 'density', 'cobalt chrome', 'tricalcium phosphate', 'biocomposite'] | Binder Saturation, Layer Thickness, Drying Time and Their Effects on Dimensional Tolerance and Density of Cobalt Chrome - Tricalcium Phosphate Biocomposite | Conference paper | https://repositories.lib.utexas.edu//bitstreams/2c4450a0-4676-4753-a451-d235a2c2cec8/download | University of Texas at Austin | Traditional metals such as stainless steel, titanium and cobalt chrome are used in
biomedical applications (implants, scaffolds etc.) but suffer from issues such as osseointegration
and compatibility with existing bone. One way to improve traditional biomaterials is to incorporate
ceramics with these metals so that their mechanical properties can be similar to cortical bones.
Tricalcium phosphate is such a ceramic with properties so that it can be used in human body. This
research explores the use of binder jetting based additive manufacturing process to create a novel
biocomposite made of cobalt chrome and tricalcium phosphate. Experiments were conducted and
processing parameters were varied to study their effect on the printing of this biocomposite. Layer
thickness, binder saturation and drying time affected the dimensional tolerance and the density of
the green samples. This effect is important to understand so that the material can be optimized for
use in specific applications. | null | null | null | null | null | null |
['Bai, Yun', 'Williams, Christopher B.'] | 2021-11-02T14:55:08Z | 2021-11-02T14:55:08Z | 2017 | Mechanical Engineering | null | https://hdl.handle.net/2152/89818 | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['binder jetting', 'nanoparticles', 'inkjet printing', 'sintering', 'copper'] | Binderless Jetting: Additive Manufacturing of Metal Parts via Jetting Nanoparticles | Conference paper | https://repositories.lib.utexas.edu//bitstreams/199dbb02-230a-4e60-a674-b8ebf54da9ab/download | University of Texas at Austin | Binder Jetting AM has been used to fabricate metal parts by first jetting a binder into
powder bed; the resulting green part is then thermally post-processed wherein the binder is
removed and the metal particles are sintered. In this work, the authors replace conventionally-used polymeric binders with nanoparticle suspensions as a means for binding metal powder bed
particles together. After being deposited into the powder particles’ interstices, the jetted
nanoparticles are sintered at a low temperature via a heated powder bed to provide strength to the
printed green part. Regions of the powder bed that do not receive the jetted nanoparticle
suspension remain as loose powder as the sintering temperature of the nanoparticles is
significantly lower than the larger powder bed particles. The concept of printing metal by jetting
a nanoparticle binder made of the same material is demonstrated in the context of copper through
printing copper parts with satisfactory green strength. | null | null | null | null | null | null |
['Kruth, J. P.', 'Mercelis, P.', 'Froyen, L.', 'Rombouts, Marleen'] | 2019-12-05T17:23:45Z | 2019-12-05T17:23:45Z | 2004 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/78651', 'http://dx.doi.org/10.26153/tsw/5707'] | eng | 2004 International Solid Freeform Fabrication Symposium | Open | Selective Laser | Binding Mechanisms in Selective Laser Sintering and Selective Laser Melting | Conference paper | https://repositories.lib.utexas.edu//bitstreams/d3cc6586-8609-4387-8b0f-d5ebbf5a91d6/download | null | Layer Manufacturing (LM) technologies like Selective Laser Sintering (SLS) were developed
in the late 80’s as techniques for Rapid Prototyping (RP). Today, SLS - as well as its derived
technology Selective Laser Melting (SLM) - is used as well for prototyping, tooling and
manufacturing purposes. This widening of applications is caused mainly by the possibility to
process a large variety of materials, resulting in a broad range of physical and mechanical
properties.
This paper presents a survey of the various binding mechanisms in SLS and SLM, which are
responsible for the broad range of materials and applications. Basic binding mechanisms involve
solid state sintering, chemically induced binding, liquid phase sintering, partial melting and full
melting. Many subcategories can be distinguished based on the type of structural or binder
powder composition: single component powder grains (single material or alloy), composite
powder grains, mixtures of different powder grains, distinct binder material (sacrificial or
permanent), etc. The paper will explain how these binding mechanisms apply for sintering
various types of materials: plastics, metal, ceramics and composites (e.g. glass reinforced
polymers, cermets, hardmetals, etc.). It gives a survey of research done at the University of
Leuven, Belgium, as well as at other European and non-European organizations. | null | null | null | null | null | null |
['Jameekornkul, P.', 'Panesar, A.'] | 2024-03-27T03:37:55Z | 2024-03-27T03:37:55Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124470', 'https://doi.org/10.26153/tsw/51078'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['additive manufacturing', 'bouligand fiber arrangement', 'honeycomb structure'] | BIO-INSPIRED AM STRUCTURE WITH CARBON FIBRE REINFORCEMENT | Conference paper | https://repositories.lib.utexas.edu//bitstreams/5bfd2951-ff59-4ac7-b35f-3cf905d01146/download | University of Texas at Austin | This study presents a novel design approach that introduces the bouligand fibre arrangement in a
honeycomb structure. This design is made possible by utilising AM technology which allows for the realisation
of complex design whilst ensuring precise control for fibre placement. Reinforced honeycomb structures with
varied incrementally twisted pitch angle of 0°,1.25°,5° and 15° were successfully fabricated and tested under outof-plane compression. Among the tested angles, the honeycomb structure oriented at 1.25° exhibited higher peak
load and higher specific energy absorption. Unlike the original untwisted honeycomb, the bio-inspired
honeycomb showed no noticeable buckling or delamination at the mid-plane, which may be due the microcracking
or resulting from a delay in crack propagation. However, the precise relationship between pitch angle and
honeycomb properties requires further investigation across a wider range of pitch angle with more focus
understanding the fracture propagation in fibre arrangement. Overall, the preliminary results indicate that the
proposed bio-inspired AM design present a promising approach to enhance the properties of honeycombs and
afford the flexibility to improve toughness and energy absorption capabilities. | null | null | null | null | null | null |
['Guo, Nannan', 'Leu, Ming C.', 'Wu, Maoliang'] | 2021-10-05T14:39:49Z | 2021-10-05T14:39:49Z | 8/17/11 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88382', 'http://dx.doi.org/10.26153/tsw/15321'] | eng | 2011 International Solid Freeform Fabrication Symposium | Open | ['fuel cells', 'polymer electrolyte membrane', 'flow fields', 'bipolar plate', 'finite element modeling'] | Bio-Inspired Design of Bipolar Plate Flow Fields for Polymer Electrolyte Membrane Fuel Cells | Conference paper | https://repositories.lib.utexas.edu//bitstreams/142c716a-8625-4cbd-a51c-b749d74fe960/download | University of Texas at Austin | The flow field of a bipolar plate distributes hydrogen and oxygen for polymer electrolyte
membrane (PEM) fuel cells and removes the produced water from the fuel cells. It greatly
influences the performance of fuel cells, especially regarding reduction of mass transport loss.
Flow fields with good gas distribution and water removal capabilities reduce the mass transport
loss, thus allowing higher power density. Inspired by natural structures such as veins in tree
leaves and blood vessels in lungs, which efficiently feed nutrition from one central source to
large areas and are capable of removing undesirable by-products, a mathematic model has been
developed to optimize the flow field with minimal pressure drop, lowest energy dissipation, and
uniform gas distribution. The model can be used to perform optimal flow field designs, leading
to better fuel cell performance for different sizes and shapes of bipolar plates. Finite element
modeling (FEM) based simulations and in-situ experiments were conducted to verify some of the
flow field designs obtained using the developed mathematic model. | null | null | null | null | null | null |
['Lee, G.', 'Barlow, J.W.', 'Fox, W.C.', 'Aufdermorte, T.B.'] | 2018-11-08T19:14:05Z | 2018-11-08T19:14:05Z | 1996 | Mechanical Engineering | doi:10.15781/T2S46HR8S | http://hdl.handle.net/2152/69907 | eng | 1996 International Solid Freeform Fabrication Symposium | Open | ['SLS', 'MRI', 'reconstruction'] | Biocompatibility of SLS-Formed Calcium Phosphate Implants | Conference paper | https://repositories.lib.utexas.edu//bitstreams/907f6f0a-3cf2-4291-8891-429666d4a170/download | null | A method for fabricating artificial calcium phosphate bone implants by the Selective Laser
Sintering (SLS) process has been developed that can fabricate complex and delicate
calcium phosphate bone facsimiles from a variety of data inputs including Computed
Tomography(CT) files (1). This paper discusses two in vivo biocompatibility studies of
SLS-formed calcium phosphate implants in both rabbits and dogs. Histologic analysis
shows a high degree of biocompatibility and bone ingrowth in both studies. | null | null | null | null | null | null |
['He, Yinfeng', 'Kilsby, Sam', 'Tuck, Chris', 'Wildman, Ricky', 'Christie, Steven', 'Yang, Hongyi', 'Edmondson, Steven'] | 2021-10-18T21:21:06Z | 2021-10-18T21:21:06Z | 2014 | Mechanical Engineering | null | https://hdl.handle.net/2152/89249 | eng | 2014 International Solid Freeform Fabrication Symposium | Open | ['biodegradable polycaprolactone based ink', 'biodegradable polycaprolactone', '3D inkjet printing', 'Additive Manufacturing', 'biomedical applications'] | A Biodegradable Polycaprolactone Based Ink Developed for 3D Ink Jetting | Conference paper | https://repositories.lib.utexas.edu//bitstreams/992bc183-550a-476b-b002-195c4048623a/download | University of Texas at Austin | Biomedical applications are one of the driving forces for Additive
Manufacturing, however to extend the range of applications and markets new
materials are required. A new type of biodegradable Polycaprolactone (PCL) based
ink that is suitable for 3D inkjet printing was successfully developed. UV curable PCL
was synthesized and mixed with Poly(ethylene glycol) di-acrylated (PEGDA) to
prepare an ink with suitable viscosity for inkjet printing. Their mechanical properties
as well as the printing accuracy were measured by nano-indentation and scanning
electron microscopy. Post curing was applied to printed samples in order to study
how post curing may influence sample properties. It was found that within 30min
post-curing period, the sample’s surface which is direct illuminated by UV light
increased from 31.22MPa to 70.20MPa while the bottom surface showed less
incensement from 34.9MPa to 39.8MPa. | null | null | null | null | null | null |
['Starly, B.', 'Lau, A.', 'Sun, W.', 'Lau, W.', 'Bradburyq, T.'] | 2020-02-17T15:36:54Z | 2020-02-17T15:36:54Z | 2004 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/80012', 'http://dx.doi.org/10.26153/tsw/7037'] | eng | 2004 International Solid Freeform Fabrication Symposium | Open | Interior Architecture Design | Biomimetic Design and Fabrication of Interior Architecture of Tissue Scaffolds Using Solid Freeform Fabrication | Conference paper | https://repositories.lib.utexas.edu//bitstreams/85971b3e-5d43-4c7e-8621-6836b4756151/download | null | Modeling, design and fabrication of tissue scaffolds with intricate architecture,
porosity and pore size for desired tissue properties presents a challenge in tissue engineering.
This paper will present the details of our development in designing and fabrication of the
interior architecture of scaffolds using a novel design approach. The Interior Architecture
Design (IAD) approach seeks to generate scaffold layered freeform fabrication tool path without
forming complicated 3D CAD scaffold models. This involves: applying the principle of layered
manufacturing to determine the scaffold individual layered process planes and layered contour;
defining the 2D characteristic patterns of the scaffold building blocks (unit cells) to form the
Interior Scaffold Pattern; and the generation of process tool path for freeform fabrication of
these scaffolds with the specified interior architecture. Feasibility studies applying the IAD
algorithm to example models and the generation of fabrication planning instructions will be
presented. | null | null | null | null | null | null |
['Delwiche, Maia', 'Obielodan, John'] | 2023-02-10T13:51:54Z | 2023-02-10T13:51:54Z | 2022 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/117446', 'http://dx.doi.org/10.26153/tsw/44327'] | eng | 2022 International Solid Freeform Fabrication Symposium | Open | ['Additive manufacturing', 'Biopolymer', 'Dairy', 'Casein', 'Polymers'] | Biopolymer Composites with Dairy Protein for Use in Additive Manufacturing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/020f269d-1ed1-47e7-84f1-da571b902c97/download | null | As the popularity and versatility of additive manufacturing grows, so does interest in
developing new materials, including biopolymers. Casein is a protein found in dairy and
historically, has been used in food applications, but its use as a biomaterial for engineering
structures is less common. This study investigates the development of composite materials for
additive manufacturing with casein as a biomaterial filler. To observe the effects of casein on
material properties, vat photopolymerization-based and fused filament fabrication-based matrix
materials were combined with different weight fractions of casein. Test samples were fabricated
to evaluate tensile properties. Test results show a maximum increase of 4% for FFF and 34% for
SLA in the stiffness of the materials with casein compared to the neat matrix materials. However,
the composite materials showed between 12% and 54% reductions in ductility, and marginal
decreases in tensile strengths. The preliminary results indicate viability and prompt further
investigation into casein-polymer composites for additive manufacturing. | null | null | null | null | null | null |
['Hoeges, S.', 'Lindner, M.', 'Meiners, W.', 'Smeets, R.'] | 2021-10-04T19:58:13Z | 2021-10-04T19:58:13Z | 9/23/10 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88330', 'http://dx.doi.org/10.26153/tsw/15269'] | eng | 2010 International Solid Freeform Fabrication Symposium | Open | ['bioresorbable implants', 'bone implants', 'additive manufacturing', 'Selective Laser Melting', 'bone surgery'] | Bioresorbable Implants using Selective Laser Melting | Conference paper | https://repositories.lib.utexas.edu//bitstreams/e45a9a14-577d-4df0-be76-1d395bbcc2fb/download | University of Texas at Austin | Using bioresorbable materials implants can be manufactured which dissolve in the human body
and are replaced by natural bone structure. For large implants an interconnecting porous structure
needs to be integrated in the implant for a good vascularisation. Using additive manufacturing
technology these internal structures can be directly manufactured. The structure can be designed
by consequent following the guidelines of the medical expert. This paper describes the development of Selective Laser Melting to process bioresorbable materials Poly(D,L-lactide) and B-Tricalciumphosphate. The properties of the parts concerning microstructure, mechanical and
biological properties after processing are analyzed in laboratory and animal tests. Possible
applications are demonstrated and include individual bone substitute implants in cranio-maxillofacial surgery. | null | null | null | null | null | null |
['Liu, J.', 'Fearon, E.', 'Edwardson, S.P.', 'Dearden, G.'] | 2021-11-04T14:12:12Z | 2021-11-04T14:12:12Z | 2017 | Mechanical Engineering | null | https://hdl.handle.net/2152/89965 | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['blown powder laser cladding', 'processing parameters', 'isotropic material', 'build height', 'powder delivery rate', 'additive manufacturing'] | Blown Powder Laser Cladding with Novel Processing Parameters for Isotropic Material Properties | Conference paper | https://repositories.lib.utexas.edu//bitstreams/2ebca7c3-6294-449d-948f-fef4e264b524/download | University of Texas at Austin | A limitation for blown powder laser additive manufacturing in many applications is the
material properties of parts made tend to show anisotropy due to directional solidification of
the microstructure. Recent work reported here has identified novel low power processing
conditions that yield equiaxed grain structures in 316L stainless steel and thus potentially
eliminate material anisotropy. Initial observations show that the process window is affected by
build height, substrate choice, powder, powder delivery rates, laser power and processing speed.
A system has been developed to give precision layer height control via nozzle design and low
powder delivery rates through an in-house design of powder hopper. Mechanical tests have
been conducted under the novel processing parameters. Large amounts and uniform
distribution of equiaxed structures compared to standard process conditions in 316L are found
significantly. Moreover, cladding has been successfully produced with significantly low power
around 350W, thus potentially improving process efficiency and set-up cost. | null | null | null | null | null | null |
['Sriraman, M.R.', 'Hiromichi, Fujii', 'Gonser, Matt', 'Babu, S.S.', 'Short, Matt'] | 2021-09-30T15:27:12Z | 2021-09-30T15:27:12Z | 9/23/10 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88263', 'http://dx.doi.org/10.26153/tsw/15204'] | eng | 2010 International Solid Freeform Fabrication Symposium | Open | ['Very High Power Ultrasonic Additive Manufacturing', 'aluminum alloys', 'copper alloys', 'layer bonding'] | Bond Characterization in Very High Power Ultrasonic Additive Manufacturing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/f1996184-5392-463a-b2bb-abc35960ffd3/download | University of Texas at Austin | Solid parts were produced by Very High Power Ultrasonic Additive Manufacturing (VHP-UAM)
at room temperature using 150 μm thick tapes of 6061 aluminum and 110 copper alloys.
Processing was done at 20 kHz frequency over a range of parameters (26 –36 μm vibration
amplitude, 5.6 – 6.7 kN normal force, and 30.5 - 35.5 mm/s travel speed). Softening of materials
(up to about 14% in 6061 Al and 23% in 110 Cu) was noted facilitating enhanced plastic flow
and a reduction in interfacial voids. Evolution of fine recrystallized grains (0.3-4 μm in 6061 Al
and 0.3-10 μm in 110 Cu) from an initial coarser grain structure (up to 8 μm in 6061 Al and 25
μm in Cu) was observed at the build interface regions. Bonding between layers in both materials
seems to have occurred by dynamic recrystallization and movement of grain boundaries across
the interface. The energy required for the above physical processes is derived from interfacial
adiabatic plastic deformation heating. | null | null | null | null | null | null |
['Walczyk, Daniel F.', 'Dolar, Nathanael Y.'] | 2018-11-29T21:00:36Z | 2018-11-29T21:00:36Z | 1997 | Mechanical Engineering | doi:10.15781/T2QR4P95D | http://hdl.handle.net/2152/70344 | eng | 1997 International Solid Freeform Fabrication Symposium | Open | ['welding', 'laminations'] | Bonding Methods for Laminated Tooling | Conference paper | https://repositories.lib.utexas.edu//bitstreams/1be7e4e5-c0bb-4ae3-9353-0aef1950a707/download | null | Laminated tooling consists of an array of stacked laminations that are mechanically
clamped or bonded together, depending on the requirements of the manufacturing process.
Various manufacturing processes that can benefit from tooling constructed oflaminations include
sheet metal forming, thermoforming, composites molding, metal extrusion, injection molding,
resin transfer molding, and compression molding. When bonding of the laminations is required
(e.g., incorporation of conformal cooling passages for injection molding temperature control)
then laminations can be joined together by diffusion bonding, brazing and using adhesives.
However, for a tooling engineer to effectively design a laminated tool, the physical and
mechanical properties of these joints must be known. Consequently, a set of experiments is
outlined for determining the tensile, shear, and peel strengths, tensile and shear elastic moduli,
thermal contact resistance, and specific permeability (for gasses or liquids) ofthe aforementioned
bonded joints for both steel and aluminum laminations. Some preliminary results with aluminum
and future work are presented. | null | null | null | null | null | null |
['Ott, M.', 'Meihöfener, N.', 'Koch, R.'] | 2023-03-30T16:06:43Z | 2023-03-30T16:06:43Z | 2022 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/117696', 'http://dx.doi.org/10.26153/tsw/44575'] | eng | 2022 International Solid Freeform Fabrication Symposium | Open | Additive manufacturing | Boosting artificial intelligence in design processes by the use of additive manufacturing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/c06599a6-b454-48f6-a52a-3e09575c2438/download | null | Additive manufacturing offers the option of converting digital prototypes into real
structures as quickly as possible by the special property of tool-free manufacturing. However, this
process can only be used at optimum speed if bottlenecks can be effectively avoided. One of these
constraints is the design process. Although modern CAD systems allow a significant increase in
many areas, this always requires a person with specific skills (e.g. engineer). In the field of AM in
particular, more and more powerful software solutions have recently been published which
accelerate the Design for Additive Manufacturing, including most CAD-tasks. In many areas,
therefore, attempts are already made to automate relevant design steps as much as possible, more
and more using neural networks and artificial intelligence. This paper presents how and why such
techniques can be used to generate three-dimensional structures quickly and efficiently in cases of
deep generative design tasks. | null | null | null | null | null | null |
['Lipton, Jeffrey I.', 'Cohen, Daniel', 'Lipson, Hod'] | 2021-09-29T18:04:36Z | 2021-09-29T18:04:36Z | 9/15/09 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88203', 'http://dx.doi.org/10.26153/tsw/15144'] | eng | 2009 International Solid Freeform Fabrication Symposium | Open | ['brick printing', 'modular architectural elements', 'embedded systems', 'open-architecture SFF'] | Brick Printing: Freeform Fabrication of Modular Architectural Elements with Embedded Systems | Conference paper | https://repositories.lib.utexas.edu//bitstreams/72ca5735-3301-4bab-89e8-83ebca726a1e/download | University of Texas at Austin | We propose the use of modular, printed bricks to enable the integration of building
systems and various processing techniques through the use of scalable printer
platforms. This is enabled by a novel material platform comprised of clay, gypsum
cement, FabEpoxy™, and SS-26F conductive silicone. On an open-architecture SFF
system, a segment of cement wall with embedded electrical and fluidic conduits and
various processing techniques was fabricated. Electrical and fluidic tolerances were
comparable to traditionally constructed systems. | null | null | null | null | null | null |
['Luo, Junjie', 'Bender, Theresa', 'Bristow, Douglas A.', 'Landers, Robert G.', 'Goldstein, Jonathan T.', 'Urbas, Augustine M.', 'Kinzel, Edward C.'] | 2021-10-28T14:31:28Z | 2021-10-28T14:31:28Z | 2016 | Mechanical Engineering | null | https://hdl.handle.net/2152/89650 | eng | 2016 International Solid Freeform Fabrication Symposium | Open | ['bubble formation', 'bubble entrapment', 'borosilicate glass', 'additive manufacturing'] | Bubble Formation in Additive Manufacturing of Borosilicate Glass | Conference paper | https://repositories.lib.utexas.edu//bitstreams/b97f2f04-6bed-4f4d-bbad-32cbae205df8/download | University of Texas at Austin | Entrapped bubbles are an important problem in conventional glass manufacturing. It is also a significant
factor determining the quality of glass products produced using additive manufacturing (AM). This paper
reports on the bubble formation and entrapment in filament-fed AM printing of borosilicate glass. This process
involves maintaining a local molten region using a CO2 laser. A 2 mm filament is fed continuously into the
molten region while CNC stages position the workpiece relative to the laser and filament feed. Two different
bubble regimes are identified in experiments with borosilicate glass. These regimes can be related to different
physical phenomena, specifically, bubble entrapment at defects in the filaments and bubble formation due to
reboil. These can be overcome by selecting defect free filaments and by minimizing the temperature inside the
molten region to prevent breaking down the glass. Understanding these mechanisms allows bubble-free glass to
be printed. Finally, residual stress in the deposited glass pieces is removed using post-deposition annealing and
validated using a polariscope. | null | null | null | null | null | null |
['Roschli, Alex', 'Post, Brian K.', 'Atkins, Celeste', 'Stevens, Adam G.', 'Chesser, Phillip', 'Zaloudek, Kristin'] | 2023-01-27T13:59:03Z | 2023-01-27T13:59:03Z | 2022 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/117333', 'http://dx.doi.org/10.26153/tsw/44214'] | eng | 2022 International Solid Freeform Fabrication Symposium | Open | ['build plate', 'build surface', 'extrusion', '3D printer design'] | Build Plate Design for Extrusion-Based Additive Manufacturing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/eee89ba5-c62e-4bfc-a37a-b274a21b27ee/download | null | A fundamental part of machine design for large format polymer extrusion-based additive
manufacturing (AM) systems is the substrate where the object is to be constructed, often referred
to as the build plate. A good build plate is imperative for a successful build as it is used for
supporting and positioning the part during the entire construction. For planar 3D printing, this
build plate needs to be flat and in-plane with the X/Y motion of the 3D printer. Additional
functionality can include heaters for preventing delamination or warping, vacuum to help prevent
warping, removable build surfaces for quick part removal, and mounting features for helping
position a part for subtractive operations. This paper reviews existing build plate designs and
discusses the design considerations and materials for build plate fabrication. | null | null | null | null | null | null |
['McClurkin, Joel E.', 'Rosen, David W.'] | 2018-12-07T16:06:52Z | 2018-12-07T16:06:52Z | 1997 | Mechanical Engineering | doi:10.15781/T2HD7PC8K | http://hdl.handle.net/2152/71442 | eng | 1997 International Solid Freeform Fabrication Symposium | Open | ['SLA', 'Build Style Optimization'] | Build Style Decision Support for Stereolithography | Conference paper | https://repositories.lib.utexas.edu//bitstreams/cbe2b51b-3e0e-4fbf-ab0b-a15815fd48d8/download | null | When building parts in a stereolithography apparatus (SLA), the user is faced with many
decisions regarding how the part will be built. The quality of the build can be controlled by the
user via changing one of several build style variables, including part orientation, cross sectional
layer thickness, and laser hatch density. A user will probably have preferences for the part build
(Le., accuracy or speed), but may not understand how to vary the build style variables to produce
the desired results. A method based on response surface methodology and multi-objective decision
support is described in this paper for relating build goals to three build style variables, and the use
ofthese relationships in providing decision support for building a part on a SLA. The method is
applied to the build style of a circuit breaker handle. | null | null | null | null | null | null |
['Mensing, G.', 'Gibson, I.'] | 2019-02-22T19:58:47Z | 2019-02-22T19:58:47Z | 1998 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/73468', 'http://dx.doi.org/10.26153/tsw/618'] | eng | 1998 International Solid Freeform Fabrication Symposium | Open | ['rapid prototyping systems', 'StereoLithography'] | Build Time Estimations for Large Scale Modelling | Conference paper | https://repositories.lib.utexas.edu//bitstreams/e9ccdbc7-9a63-431f-92ca-a285750f03c1/download | null | Achieving speedy results in model making is very much desired if not a necessity in ahnost any
manufacturing industry. There is no doubt that rapid prototyping contributes to this process. It is
generally considered that when compared to conventional machining techniques like nlilling, the
current rapid prototyping systems appear to be much faster. This is certainly true for complex,slnall
objects. I-Iowever, this is not alwaysa,pplicable to simple, large and bulky parts.
There are a number of projects and systems concentrating on the fabrication of large models. Work
is being carried out at the University ofHong Kong, using milling. along with slicing technology.
This.report compares some ofthe rapid prototyping systems witl1milling. Milling is an established
technology and recent developments in materials and nlachines used in Inilling nlake it a good
alternative to rapid prototyping when itcomes to largesyale nl0delling. | null | null | null | null | null | null |
['Li, Yingqi', 'Shen, Yiyu', 'Leu, Ming C.', 'Tsai, Hai-Lung'] | 2021-11-02T19:46:04Z | 2021-11-02T19:46:04Z | 2017 | Mechanical Engineering | null | https://hdl.handle.net/2152/89880 | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['metallic glass', 'titanium', 'laser welding', 'embrittlement', 'additive manufacturing'] | Building Zr-Based Metallic Glass Part on Ti-6Al-4V Substrate by Laser-Foil-Printing Additive Manufacturing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/facfccd8-bb78-4ef6-b4b6-3892c4656cb0/download | University of Texas at Austin | Through using Zr intermediate layers, Zr52.5Ti5Al10Ni14.6Cu17.9 metallic glass (MG) parts are
successfully built on Ti-6Al-4V substrate by laser-foil-printing (LFP) additive manufacturing
technology in which MG foils are laser welded layer-by-layer onto the substrate. The printed MG
part is free of porosity, cracking and crystallization, and its properties are very similar to the
original MG material. The Zr intermediate layers are aimed at preventing direct interaction
between the first layer of MG foil and the Ti substrate; otherwise, the welded MG foils would peel
off from the substrate due to the formation of brittle intermetallic compounds. With the use of Zr
intermediate layers, the bonding strength of the printed MG part and the Ti substrate can reach 758
MPa owing to the formation of α-Zr phase. | null | null | null | null | null | null |
['Choi, Sangeun', 'Hebbar, Ravi', 'Zheng, Yong', 'Newman, Wyatt S.'] | 2018-12-07T16:11:52Z | 2018-12-07T16:11:52Z | 1997 | Mechanical Engineering | doi:10.15781/T2804Z53B | http://hdl.handle.net/2152/71444 | eng | 1997 International Solid Freeform Fabrication Symposium | Open | ['CAD', 'SDM'] | CAD and Control Technologies for Computer-Aided Manufacturing of Laminated Engineering Materials | Conference paper | https://repositories.lib.utexas.edu//bitstreams/74d442b8-0888-4062-8bac-8b51d3cd162a/download | null | This paper presents recent progress in software, material handling and tangent-cutting control in
support of Computer-Aided Manufacturing of Laminated Engineering Materials(CAM-LEM).
Progress in CAD focuses on the definition of a new layered file format for describing 3-D solids in
terms of thick slabs with ruled-surface edges. For material handling, we present new algorithms
for automatic generation of mask hole patterns used in selective-area vacuum gripping, which is
required for our laminated assembly process. Finally, we present recent results of object
fabrication using thick-slab, tangent-cut layers | null | null | null | null | null | null |
['Koch, P.', 'Korn, H.', 'Kordass, R.', 'Holtzhausen, S.', 'Schoene, C.', 'Mueller, B.', 'Stelzer, R.'] | 2021-11-09T20:22:10Z | 2021-11-09T20:22:10Z | 2018 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90156', 'http://dx.doi.org/10.26153/tsw/17077'] | eng | 2018 International Solid Freeform Fabrication Symposium | Open | ['CAD-based workflow', 'CAD', 'mechanical characterization', 'lattice structures', 'laser beam melting', 'additive manufacturing'] | A CAD-Based Workflow and Mechanical Characterization for Additive Manufacturing of Tailored Lattice Structures | Conference paper | https://repositories.lib.utexas.edu//bitstreams/c2854ec4-ff96-42cc-8521-536b58fcf0ac/download | University of Texas at Austin | Lattice structures are highly recommended for lightweight applications and cost reduction
in additive manufacturing (AM). Currently, parts with lattice structures are still mainly used for
illustrative purposes and rarely in industrial products. One important reason is that, due to their
high dependency on macro- and micro-geometry, the mechanical properties of manufactured
structures are difficult to predict. Thus, even and precise struts are needed. In this paper, a workflow
for fabrication of lattice structures with strut-diameters from 150 µm to 400 µm on commercial
laser beam melting (LBM) systems is presented. Based on a CAD-integrated user-interface for
lattice design, a customized slicing algorithm determines database-aided suitable exposure
parameters which ensure that the properties of the manufactured struts will just be as specified
upon design. Subsequently, compression tests are performed in order to verify the established
workflow. The developed tool enables designers to integrate AM-specific geometries into their
components with little specific experience in AM. | null | null | null | null | null | null |
['Quigley, Tiffany', 'Penney, Joshua', 'Goodspeed, Devon', 'Cornelius, Aaron', 'Hamel, William', 'Schmitz, Tony', 'Jared, Bradley'] | 2023-01-26T14:58:16Z | 2023-01-26T14:58:16Z | 2022 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/117313', 'http://dx.doi.org/10.26153/tsw/44194'] | eng | 2022 International Solid Freeform Fabrication Symposium | Open | WAAM | CAD-to-Scan Planning for Hybrid Manufacturing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/88468c5b-da74-442e-9dca-41587730f8c5/download | null | The University of Tennessee, Knoxville (UT) has developed a hybrid manufacturing work
cell incorporating wire-arc additive manufacturing (WAAM), fringe projection scanning and 5-
axis machining. Integrating metrology into the hybrid manufacturing work cell enables
optimization of printed part placement for machining and/or supplementary material, when
necessary, via additional deposition. This presentation will explore path planning for efficient
imaging of printed geometries. The acquired scans are then polygonized and compared to the
desired geometry which is utilized in defining machining areas with excess material or underbuilt
areas for additional material deposition via gas metal arc welding (GMAW). | null | null | null | null | null | null |
['Zhou, Chi', 'Chen, Yong'] | 2021-09-28T18:45:32Z | 2021-09-28T18:45:32Z | 9/15/09 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88150', 'http://dx.doi.org/10.26153/tsw/15091'] | eng | 2009 International Solid Freeform Fabrication Symposium | Open | ['Solid Freeform Fabrication', 'large-area mask projection stereolithography', 'digital light processing', 'calibration'] | Calibrating Large-area Mask Projection Stereolithography for Its Accuracy and Resolution Improvements | Conference paper | https://repositories.lib.utexas.edu//bitstreams/94990696-ae14-459e-bf8d-91514dfb1d16/download | University of Texas at Austin | Solid freeform fabrication (SFF) processes based on mask image projection such as digital
micro-mirror devices (DMD) have the potential to be fast and inexpensive. More and more research
and commercial systems have been developed based on such digital devices. However, a digital light
processing (DLP) projector based on DMD has limited resolution and certain image blurring. In order
to use a DLP projector in the large-area mask projection stereolithography, it is critical to plan mask
images in order to achieve high accuracy and resolution. Based on our previous work on optimized
pixel blending, we present a calibration method for capturing the non-uniformity of a projection image
by a low cost off-the-shelf DLP projector. Our method is based on two calibration systems, a
geometric calibration system that can calibrate the position, shape, size, and orientation of a pixel and
an energy calibration system that can calibrate the light intensity of a pixel. Based on both results, the
light intensity at various grayscale levels can be approximated for each pixel. Developing a library of
such approximation functions is critical for the optimized pixel blending to generate a better mask
image plan. Experimental results verify our calibration results. | null | null | null | null | null | null |
['Torabi, Payman', 'Petros, Matthew', 'Khoshnevis, Behrokh'] | 2021-10-12T22:20:23Z | 2021-10-12T22:20:23Z | 2014 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88754', 'http://dx.doi.org/10.26153/tsw/15688'] | eng | 2014 International Solid Freeform Fabrication Symposium | Open | ['Selective Inhibition Sintering', 'Additive Manufacturing', 'piezo-electric printhead', 'metal parts', 'Design of Experiments'] | Calibration of a Piezo-Electric Printhead in the Selective Inhibition Sintering (SIS) Process for Fabrication of High Quality Metallic Parts | Conference paper | https://repositories.lib.utexas.edu//bitstreams/30e6d444-6ac0-4faf-bb6d-c4b2533c28ed/download | University of Texas at Austin | Selective Inhibition Sintering (SIS) is a disruptive Additive Manufacturing process capable of
printing parts from polymers, metals and ceramics. In this paper the application of a commercial
piezo-electric printhead in SIS-metal is studied. This replaces the single-nozzle solenoid valve
previously used in the process and allows the fabrication of high quality metallic parts due to
smaller droplet sizes as well as high resolution printing mechanisms. A Design of Experiments
(DoE) approach has been utilized to study the effects of important factors in printing the
inhibitor. These factors include: composition of the inhibitor, quality of the print, and amount of
fluid deposited for each layer. Based on the results of these experiments, parameters have been
identified for the creation of highly accurate three-dimensional parts. | null | null | null | null | null | null |