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['Magadum, Sunil', 'Gilorkar, Amol', 'Deepak, M.', 'Rakshith, B.S.', 'Navaharsha, P.', 'Nagahanumaiah', 'Somashekara, M.A.'] | 2021-11-30T22:18:30Z | 2021-11-30T22:18:30Z | 2021 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90568', 'http://dx.doi.org/10.26153/tsw/17487'] | eng | 2021 International Solid Freeform Fabrication Symposium | Open | ['3D printing', 'mechanical metamaterials', 'chiral', 're-entrant', 'hybrid model'] | Design, Simulation and Experimental Investigation of 3D Printed Mechanical Metamaterials | Conference paper | https://repositories.lib.utexas.edu//bitstreams/0bdcd8f3-265f-430a-a249-e511113716ae/download | University of Texas at Austin | Mechanical metamaterials have generated special interest recently due to their tailorable
structure, exceptional mechanical properties, and advancements in 3D printing processes that allow
the fabrication of intricately structured components. Designing innovative structures of metamaterials
will lead to the development of advanced materials with special properties. The experimental
investigation presented in this paper involves the design, simulation, fabrication, and testing of three
different mechanical metamaterial models i.e. Chiral, Re-entrant, and Hybrid printed in acrylonitrile
styrene acrylate (ASA) using fused deposition modeling (FDM). Subsequently, a uniaxial
compression test and ex-situ characterization was performed for studying the mechanical properties,
the types of fracture and crack propagation of the printed metamaterial models which may lead to the
development of metamaterials with tunable compressive/bending stiffness. | null | null | null | null | null | null |
['McMillen, Devin', 'Li, Wenbin', 'Leu, Ming C.', 'Hilmas, Gregory E.', 'Watts, Jeremy'] | 2021-10-28T14:11:09Z | 2021-10-28T14:11:09Z | 2016 | Mechanical Engineering | null | https://hdl.handle.net/2152/89644 | eng | 2016 International Solid Freeform Fabrication Symposium | Open | ['ceramic on-demand extrusion', 'zirconium diboride', 'ceramic powders', 'pre-ceramic organics'] | Designed Extrudate for Additive Manufacturing of Zirconium Diboride by Ceramic On-Demand Extrusion | Conference paper | https://repositories.lib.utexas.edu//bitstreams/5202f12e-1517-4cbe-a12d-af69da16abe4/download | University of Texas at Austin | This work describes a process by which zirconium diboride (ZrB2) parts may be fabricated
using the Ceramic On-Demand Extrusion (CODE) process. An oxide-carbide-nitride system
consisting of ceramic powders and pre-ceramic organics, designed to yield ZrB2 after reaction
sintering, has been developed to produce an aqueous-based extrudate for subsequent processing in
the CODE system. Pressurelessly sintered test specimens containing 1 wt% PVA binder achieve
high relative density ≥ 99%. The viscoelastic response of the extrudate was characterized via
spindle rheometry with a small sample adapter. Batches with 1 wt% PVA and 0.5 wt% Methocel
show strong shear thinning characteristic, under shear rates of 1-28 s-1. XRD and SEM were
utilized for microstructural analysis to determine phase development and microstructural
morphology. | null | null | null | null | null | null |
['Seepersad, Carolyn Connor', 'Govett, Tyler', 'Kim, Kevin', 'Lundin, Michael', 'Pinero, Daniel'] | 2021-10-06T22:39:55Z | 2021-10-06T22:39:55Z | 2012 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88463', 'http://dx.doi.org/10.26153/tsw/15400'] | eng | 2012 International Solid Freeform Fabrication Symposium | Open | ['Additive Manufacturing', 'selective laser sintering', 'tolerancing', 'dimensioning', 'design for additive manufacturing'] | A Designer's Guide for Dimensioning and Tolerancing SLS Parts | Conference paper | https://repositories.lib.utexas.edu//bitstreams/5164ba51-213c-4976-a217-40d025680b0c/download | University of Texas at Austin | Because additive manufacturing (AM) is a relatively novel industry, with the first
commercial machines introduced in the late 1980s, many designers are unaware of the
capabilities of AM technologies. Many engineers also find it difficult to utilize AM because of a
lack of “Design for AM” knowledge in the public domain. Reliable information on material
properties, dimensions and tolerances, and other process-related specifications is often scattered
throughout the literature, if it is publicly available at all. The objective of the research reported
in this paper is to begin to create a designer's guide for dimensioning and tolerancing parts that
are additively manufacturing using selective laser sintering (SLS) technology. The guide is
based on a series of experiments designed to determine the limiting feature sizes for various
types of features fabricated in commercially available SLS machines. The features include slits,
holes, letters, mating gears, and shafts built in a preassembled state. The impact of part
thickness, orientation, clearance, and dimensions on the resolvability of features is examined.
Results are reported in a series of matrices that relate realizable feature sizes to other important
variables such as part thickness. | null | null | null | null | null | null |
['Leutenecker-Twelsiek, B.', 'Klahn, C.', 'Meboldt, M.'] | 2021-10-28T22:48:28Z | 2021-10-28T22:48:28Z | 2016 | Mechanical Engineering | null | https://hdl.handle.net/2152/89723 | eng | 2016 International Solid Freeform Fabrication Symposium | Open | ['Concept Tool', 'additive manufacturing', 'product development'] | Designing a Power Tool to Show the Potentials of Additive Manufacturing - Effects of Additive Manufacturing on the Product Development Process | Conference paper | https://repositories.lib.utexas.edu//bitstreams/2b98bae6-eacd-4a15-8e26-9ba036e07cf2/download | University of Texas at Austin | Today Additive Manufacturing (AM) is mainly used for rapid prototyping and
specialized parts for industrial and end-user applications. To communicate the design potentials of
AM to a general audience it is useful to demonstrate it with a visionary product, similar to the
concept cars of the automotive industry. We have redesigned a power tool to show the benefits of
AM on an end-user product. This paper describes the Concept Tool, its different sub-systems and
highlights the range of AM’s applications. Furthermore we present our observations and findings
during the product development process. Based on these findings a design supporting system is
suggested to improve the development process for additive manufactured products. | null | null | null | null | null | null |
['kumar, Ashok V.', 'Lee, Jongho'] | 2019-09-23T16:54:11Z | 2019-09-23T16:54:11Z | 2000 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/75969', 'http://dx.doi.org/10.26153/tsw/3068'] | eng | 2000 International Solid Freeform Fabrication Symposium | Open | Prototyping | Designing and Slicing Heterogeneous Components for Rapid Prototyping 428 | Conference paper | https://repositories.lib.utexas.edu//bitstreams/56fc56bb-5412-4351-9001-3e643706f8a5/download | null | Many rapid prototyping techniques have the potential for fabricating components whose composition is non-uniform and varies in a desired fashion. A shape and composition modeling technique was developed to enable the representation and design of such heterogeneous components. Techniques for interactively and automatically designing such components are presented. Automatic design is made possible using optimization techniques where the optimal composition distribution is computed based on specified design objective and constraints. Software was also developed to slice 3D heterogeneous solids to generate cross-sectional images as well as composition distribution for each cross-section. Slicing and generation of cross-sectional data are essential to enable rapid prototyping of these components. | Partial funding from ONR contract N00014-98-1-0694 and NSF contract DMI-9875445 is gratefully acknowledged. | null | null | null | null | null |
['Xu, Xiaorong', 'Sachs, Emanuel', 'Allen, Samuel', 'Cima, Michael'] | 2019-02-19T19:39:30Z | 2019-02-19T19:39:30Z | 1998 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/73436', 'http://dx.doi.org/10.26153/tsw/588'] | eng | 1998 International Solid Freeform Fabrication Symposium | Open | ['3D Printed tools', 'heat transfer'] | Designing Conformal Cooling Channels for Tooling | Conference paper | https://repositories.lib.utexas.edu//bitstreams/d00c1807-0c98-41c5-8ffb-7531bd6df5e6/download | null | SFF technologies have demonstrated the potential to produce tooling with cooling
channels which are conformal to the molding cavity. 3D Printed tools with conformal cooling
channels have demonstrated simultaneous improvements in production rate and part quality as
compared with conventional production tools. Conformal Cooling lines of high performance
and high complexity can be created, thus presenting a challenge to the tooling designer. This
paper presents a systematic, modular, approach to the design of conformal cooling channels.
Recognizing that the cooling is local to the surface of the tool, the tool is divided up into
geometric regions and a channel system is designed for each region. Each channel system is
itself modeled as composed of cooling elements, typically the region spanned by two channels.
Six criteria are applied including; a transient heat transfer condition which dictates a maximum
distance from mold surface to cooling channel, considerations of pressure and temperature drop
along the flow channel and considerations of strength of the mold. These criteria are treated as
constraints and successful designs are sought which define windows bounded by these
constraints. The methodology is demonstrated in application to a complex core and cavity for
injection molding. | null | null | null | null | null | null |
['Sato, Shoichi', 'Togo, Naoyuki', 'Yamanaka, Shunji'] | 2021-10-28T22:03:26Z | 2021-10-28T22:03:26Z | 2016 | Mechanical Engineering | null | https://hdl.handle.net/2152/89712 | eng | 2016 International Solid Freeform Fabrication Symposium | Open | ['functional beauty', 'mass-customized products', 'running-specific prostheses', 'additive manufacturing'] | Designing Functional Beauty Through Additive Manufacturing: Prototyping of Running-Specific Prostheses Using Selective Laser Sintering | Conference paper | https://repositories.lib.utexas.edu//bitstreams/b47ed3ae-1416-41a2-b670-b36ae4db4573/download | University of Texas at Austin | The objective of this research is to establish a new methodology of designing
aesthetically and functionally satisfying mass-customized products that fit individual bodies. The
primal phase of this study, the prototyping of additive manufactured Running-Specific Prostheses
(RSPs), is shown in this paper. The focus of this work is to present the capability of
manufacturing such products by using Additive Manufacturing (AM), especially Laser
Sintering (LS). The first section describes the method in which a design process that uses AM
technologies is established, aiming mainly to achieve a functional product that is also
aesthetically pleasing. The latter section presents engineering verifications of previously designed
prostheses, and the application of structural improvements to achieve enough reliability for user
tests. The improved prosthesis was tested by a transtibial amputee runner; user review and
remaining issues are reported. | null | null | null | null | null | null |
['Spierings, A.B.', 'Wegener, K.', 'Levy, G.'] | 2021-10-06T19:58:09Z | 2021-10-06T19:58:09Z | 8/16/12 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88427', 'http://dx.doi.org/10.26153/tsw/15364'] | eng | 2012 International Solid Freeform Fabrication Symposium | Open | ['Additive Manufacturing', 'Selective Laser Melting', 'stainless steel', 'material properties'] | Designing Material Properties Locally with Additive Manufacturing Technology SLM | Conference paper | https://repositories.lib.utexas.edu//bitstreams/19c07a83-d9f5-4225-b6bc-4058df2482ce/download | University of Texas at Austin | Additive Manufacturing technologies are known to allow the production of parts with an extreme
degree of complexity, enabling design and functional part optimization. So far the development of
processing parameters and analyze of corresponding materials focuses on dense materials for
maximized material properties. However, AM processes like Selective Laser Melting, allow also the
generation of materials with some degree of porosity affecting their mechanical properties. A DOE was
set up for SLM processed SS 17-4PH / AISI-630 material with porosity between 0% and about 26% in
order to analyze mechanical properties. The results presented show that the porosity significantly
affects material ductility and hardness, offering the possibility to design a material according to the
required mechanical behavior of the parts produced. Therefore, this AM enabling features allows a
multi-property component design by appropriate local parameter setting. | null | null | null | null | null | null |
['Koers, T.', 'Magyar, B.'] | 2024-03-25T22:06:38Z | 2024-03-25T22:06:38Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124312', 'https://doi.org/10.26153/tsw/50920'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['FDM', 'fused deposition modeling', 'shrinkage', 'additive manufacturing', '2023 Solid Freeform Fabrication Symposium'] | DETERMINATION AND COMPENSATION OF THE SHRINKAGE BEHAVIOR OF CYLINDRICAL ELEMENTS IN THE FDM PROCESS | Conference paper | https://repositories.lib.utexas.edu//bitstreams/64cdbe9e-62a5-4a6d-a9f5-98ba768d23e8/download | University of Texas at Austin | Fused Deposition Modeling (FDM) is an additive manufacturing process to produce
complex thermoplastic geometries layer by layer. The filament is melted in a nozzle, iteratively
deposited, and then cools down. Due to the solidification process, the deposited filament strands
deviate from their intended position due to shrinkage, resulting in significant geometric deviations
in the final part. In terms of dimensional accuracy, there is a need for optimization, especially for
local curved geometries in relation to the global part with higher nominal dimensions. The aim of
this study is to investigate the size and shape deviations for cylindrical FDM elements and to
compensate the expected deformations by using an in-house software with adaptive scaling factors
in the x-y plane. Previous studies mainly focus on simple, non-curved objects, this study also
considers the influence of curvature and global as well as local deviations on the final part. | null | null | null | null | null | null |
['Zhang, Wei', 'Sui, Guanghua', 'Leu, Ming C.'] | 2019-09-23T17:15:08Z | 2019-09-23T17:15:08Z | 2000 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/75979', 'http://dx.doi.org/10.26153/tsw/3078'] | eng | 2000 International Solid Freeform Fabrication Symposium | Open | Prototyping | Determination and Improvement of Building Speed in Rapid Freeze Prototyping 514 | Conference paper | https://repositories.lib.utexas.edu//bitstreams/545bff11-7c01-446d-a7b8-81f42119b2d1/download | null | Rapid freeze prototyping (RFP) is a solid freeform fabrication process that builds an ice part by rapidly freezing water in a layer by layer manner. One advantage of this process is the ability to build ice parts faster than other SFF processes. The factors that affect the speed of contour building and interior filling in RFP are identified. The influence of these factors is
analyzed through heat transfer and material flow analyses. A model based on heat transfer analysis is proposed to determine the maximum achievable speed of contour building under stable conditions. Experiments are conducted to validate the performance of the proposed model for determination of building speed. | null | null | null | null | null | null |
['Le, Thao', 'Bhate, Dhruv', 'Parsey, John M.', 'Hsu, Keng H.'] | 2021-11-04T19:34:16Z | 2021-11-04T19:34:16Z | 2017 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90011', 'http://dx.doi.org/10.26153/16932'] | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['honeycomb structures', 'material modulus', 'shape', 'size', 'additive manufacturing'] | Determination of a Shape and Size Independent Material Modulus for Honeycomb Structures in Additive Manufacturing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/e8e76c3c-0155-4ad9-a9f6-642842ce68da/download | University of Texas at Austin | Most prior work on modeling cellular structures either assumes a continuum model or
homogenizes “effective” cell behavior. The challenge with the former is that bulk properties do
not always represent behavior at the scale of the cellular member, while homogenization results in
models that are shape specific and offer little insight into practical design matters like transitions
between shapes, partial cells or skin junction effects. This paper demonstrates the strong
dependence of measured properties on the size of the honeycomb specimen used for experimental
purposes and develops a methodology to extract a material modulus in the presence of this
dependence for three different honeycomb shapes. The results in this paper show that the extracted
modulus for each shape converges as the number of cells in the specimen increases and further,
that the converging values of the material moduli derived from the three shapes are within 10% of
each other. | null | null | null | null | null | null |
['Sparks, Todd', 'Pan, Heng', 'Liou, Frank'] | 2020-02-21T16:10:46Z | 2020-02-21T16:10:46Z | 8/3/05 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/80067', 'http://dx.doi.org/10.26153/tsw/7089'] | eng | 2005 International Solid Freeform Fabrication Symposium | Open | powder delivery system | Determination of Dynamic Powder Modeling Parameters via Optical Methods | Conference paper | https://repositories.lib.utexas.edu//bitstreams/1b0e85c8-fde6-42f3-b916-115b58c876d0/download | null | null | null | null | null | null | null | null |
['Yamauchi, Yuki', 'Kigure, Takashi', 'Niino, Toshiki'] | 2024-03-25T22:08:30Z | 2024-03-25T22:08:30Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124313', 'https://doi.org/10.26153/tsw/50921'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['PBF-LB/P', 'laser', 'infrared', 'additive manufacturing'] | DETERMINATION OF INPUT LASER ENERGY FOR MELTING POWDER LAYERS OF VARIOUS THICKNESSES IN HIGH-SPEED PBF-LB/P USING NEARINFRARED LASER AND ABSORBENT | Conference paper | https://repositories.lib.utexas.edu//bitstreams/96589552-a18d-4250-8ac5-558e6d1c5fb0/download | University of Texas at Austin | The rate of production of PBF-LB/P can be increased by increasing the layer thickness.
However, this reduces the part resolution in the stacking direction. To obtain both a high rate
of production and high part resolution, layer thickness adjustment in accordance with part
geometry can be effective. Optimizing the input laser energy with respect to the layer thickness
ensures sufficient melting and part strength. According to previous studies, the use of a nearinfrared laser and absorbent can increase penetration depth or depth of fusion. However, the
optical properties of the powder bed can vary significantly depending on the layer thickness,
and, therefore, the input energy that actually contributes to melting also changes with layer
thickness. This study proposes a method for determining the input laser energy for various layer
thickness without trial and error by estimating the amount of energy required to melt the powder
layer while accounting for the optical properties of the bed. | null | null | null | null | null | null |
['Obielodan, J.O.', 'Stucker, B.E.'] | 2021-09-30T15:14:05Z | 2021-09-30T15:14:05Z | 9/23/10 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88261', 'http://dx.doi.org/10.26153/tsw/15202'] | eng | 2010 International Solid Freeform Fabrication Symposium | Open | ['dissimilar material systems', 'material systems joints', 'laser metal deposition', 'dual-material structures', 'Ti6Al4V', 'Ti6Al4V/10%TiC', 'laser engineering net shaping', 'tensile strength'] | Determination of the Optimum Joint Design for LENS Fabricated Ti6Al4V and Ti6Al4V/TiC Dual-Material Structures | Conference paper | https://repositories.lib.utexas.edu//bitstreams/1bea6030-e104-4651-a093-d35e655aa68c/download | University of Texas at Austin | Joints between dissimilar material systems made using laser metal deposition processes
have been investigated. The fusion of materials with different physical properties and chemical
compositions under high laser power often results in defects at the joints. Although some
solutions have been suggested in previous work for defect-free fabrications, most of the joints
studied have been characterized using qualitative techniques only. Quantitative study is
imperative for predicting the mechanical behavior of fabricated structures for real life
applications. In this work, tensile and flexural specimens made of different Ti6Al4V and
Ti6Al4V/10%TiC dual-material transition joint designs were fabricated using laser engineered
net shaping (LENS) and tested. It was found that transition joint design has a significant effect
on the tensile strengths of dual-material structures. | null | null | null | null | null | null |
['Vijayan, Ajay Panackal Padathu', 'Sparks, Todd', 'Ruan, Jianzhong', 'Liou, Frank'] | 2020-03-05T19:26:14Z | 2020-03-05T19:26:14Z | 2006 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/80145', 'http://dx.doi.org/10.26153/tsw/7166'] | eng | 2006 International Solid Freeform Fabrication Symposium | Open | Laser Aided Manufacturing Process | Determination of Transformation Matrix in a Hybrid Multi-Axis Laser-Aided Manufacturing System and its Practical Implementation | Conference paper | https://repositories.lib.utexas.edu//bitstreams/7927e540-cae4-4da6-9e13-67d36092a717/download | null | null | null | null | null | null | null | null |
['Morris, C.', 'Cormack, J.M.', 'Hamilton, M.F.', 'Haberman, M.R.', 'Seepersad, C.C.'] | 2021-11-02T17:57:10Z | 2021-11-02T17:57:10Z | 2017 | Mechanical Engineering | null | https://hdl.handle.net/2152/89839 | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['microstereolithography', "complex young's modulus", 'material parameters'] | Determining the Complex Young’s Modulus of Polymer Materials Fabricated with Microstereolithography | Conference paper | https://repositories.lib.utexas.edu//bitstreams/7ace06d7-6760-4580-8b04-275c375efd10/download | University of Texas at Austin | Microstereolithography is capable of producing millimeter-scale polymer parts having
micron-scale features. Material properties of the cured polymers can vary depending on build
parameters such as exposure time and laser power. Current techniques for determining the
material properties of these polymers are limited to static measurements via
micro/nanoindentation, leaving the dynamic response undetermined. Frequency-dependent
material parameters, such as the complex Young’s modulus, have been determined for other
relaxing materials by measuring the wave speed and attenuation of an ultrasonic pulse traveling
through the materials. This method is now applied to determine the frequency-dependent
material parameters of polymers manufactured using microstereolithography. Because the
ultrasonic wavelength is comparable to the part size, a model that accounts for both geometric
and viscoelastic effects is used to determine the material properties using experimental data. | null | null | null | null | null | null |
['Kumar, Jeevan', 'Huseynov, Orkhan', 'Fidan, Ismail', 'Rajabali, Ismail'] | 2024-03-25T22:33:18Z | 2024-03-25T22:33:18Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124324', 'https://doi.org/10.26153/tsw/50932'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['PLA', 'LCMMEX', 'iron', 'additive manufacturing'] | Developing Additively Manufactured Iron Powder-filled PLA Composites | Conference paper | https://repositories.lib.utexas.edu//bitstreams/1d22d998-fea6-459b-978b-7f8d55317a68/download | University of Texas at Austin | The Low-Cost Metal Material Extrusion (LCMMEX) process has gained attention in
recent years to produce metallic parts with complex designs. High Iron concentration
composite materials have been extensively researched to improve their properties and
functionality for advanced manufacturing applications. This study aims to develop knowledge
blocks for producing composite parts with high iron percentages and analyze their physical
properties based on print parameters. A rectangular sample is manufactured using the Material
Extrusion (MEX) process, with variations in layer height, infill density, and print speed. The
investigation shows that a number of parameters affects the change in surface roughness,
weight, and dimensional accuracy of the printed parts. Furthermore, an increase in the infill
percentage leads to a significant increase in magnetic flux. This research study provides
insights into the influence of print parameters on the properties of high-iron-filled composite
parts, ideal for high-density applications. | null | null | null | null | null | null |
['Knapp, Mary E.', 'Wolff, Ryan', 'Lipson, Hod'] | 2021-09-23T22:50:51Z | 2021-09-23T22:50:51Z | 9/10/08 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88047', 'http://dx.doi.org/10.26153/tsw/14988'] | eng | 2008 International Solid Freeform Fabrication Symposium | Open | ['printable content', 'open wiki-style website', 'educational archive'] | Developing printable content: A repository for printable teaching models | Conference paper | https://repositories.lib.utexas.edu//bitstreams/ee82351f-cbe3-433c-bf1c-50a25dc576e5/download | null | Alongside the development of RP technology, there is an increasing need to develop and
share printable content. Like digital photography and digital music, content drives
technology as much as technology drives content. This paper describes the development
and population of an open wiki-style website (3Dprintables.org) that houses an archive of
printable models for education. Teaching models were chosen as the initial focus for this
effort for two key reasons. First, quality educational models are difficult for teachers to
obtain due to high prices, limited availability, and limited customization options; and
second, many studies have demonstrated that learning is enhanced when students interact
with physical models. Such models are also indispensible tools for teaching the visually
impaired and those with spatial reasoning difficulties. At present, the website contains
models relevant to mechanical engineering, aerospace, biochemistry, mathematics,
anatomy, and archaeology (e.g. proteins, airfoils, kinematics models, cuneiform tablets).
These models are intended to serve as "seeds" to encourage educators to further develop
and share printable models and the associated curricular materials. | null | null | null | null | null | null |
['Takagi, Tarou', 'Yashiki, Tatsuro', 'Nagumo, Yasushi', 'Numata, Shouhei', 'Sadaoka, Noriyuki'] | 2019-10-24T18:09:07Z | 2019-10-24T18:09:07Z | 2002 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/77414', 'http://dx.doi.org/10.26153/tsw/4503'] | eng | 2002 International Solid Freeform Fabrication Symposium | Open | Hydraulic Pump | Development of 3D Bit-Map-Based CAD and Its Application to Hydraulic Pump Model Fabrication | Conference paper | https://repositories.lib.utexas.edu//bitstreams/3e705fad-3c04-4ae0-8836-bda0028f6c89/download | null | A novel 3D bit-map-based CAD has been developed. This program, named CellCAD,
relies on techniques which provides easy manipulation of huge sized 3D bit-map, poly-triangle
and 2D bit-map data. It can be attached to various kinds of additional plug-in processors to
extend its functions and to customize it highly for broad applications. CellCAD can be applied
in fields using computed tomography digitizers and/or layering fabricators. The authors applied
CellCAD to hydraulic pump model fabrication. This paper reports the basic design concept and
implementation techniques of CellCAD from the viewpoint of design engineering, and also
introduces the methods and results of an actual CellCAD application. | null | null | null | null | null | null |
['Dwivedi, Indira', 'Dwivedi, Rajeev', 'Dwivedi, Bharat', 'Rebbapragada, Arun', 'Rebbapragada, Arka'] | 2024-03-27T16:10:22Z | 2024-03-27T16:10:22Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124503', 'https://doi.org/10.26153/tsw/51111'] | en | 2023 International Solid Freeform Fabrication Symposium | Open | ['3D printing', 'robotics', 'education', 'competition', 'additive manufacturing'] | Development of 3D Printable Part Library for Easy to Manufacture Components for Educational and Competitive Robotics | Conference paper | https://repositories.lib.utexas.edu//bitstreams/2180edc1-5bc0-4adb-b539-b500cb14fddd/download | University of Texas at Austin | Educational and competitive robotics enable hands on learning and experimentation. Despite cost
effective and ease of access of open source micro-controllers, drives and sensors, the structural
components and brackets continue to be very expensive. Motivated by the Robotics for Everyone
initiative, we are developing many easy-to-manufacture parts that will allow learners to easily 3D
print parts for (1) Structural assembly of robot chassis (2) Sensor mounting (3) Electronic control
mounting (4) Power supply (5) Various power drives. The ecosystem of the robotic components is
developed around extrusion structures and tubular elements and 3D printing is used for building the
parts for testing and qualifying. Fixtures for mounting cameras for advanced machine learning and
computer vision experiments are provided. | null | null | null | null | null | null |
['Yang, Li', 'Zhang, Shanshan', 'Oliveira, Gustavo', 'Stucker, Brent'] | 2021-10-07T18:45:04Z | 2021-10-07T18:45:04Z | 2013 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88502', 'http://dx.doi.org/10.26153/tsw/15436'] | eng | 2013 International Solid Freeform Fabrication Symposium | Open | ['dental restorations', 'additive manufacturing', 'porcelain powder', 'sintering', '3D printing'] | Development of a 3D Printing Method for Production of Dental Application | Conference paper | https://repositories.lib.utexas.edu//bitstreams/773b4c3f-1c92-4d04-ae42-82513c1428da/download | University of Texas at Austin | Traditionally, the manufacturing of dental restorations, including crowns, veneers and
other structures made by ceramics, is a labor‐intensive and time consuming process.
Additive manufacturing has the potential to significantly decrease the time and cost
associated with this process. This work performed preliminary investigation for the
feasibility of dental restoration parts printing using the ExOne M‐Lab system with a
commercialized dental porcelain powder. The porcelain powders were characterized,
and two measurements, including pre‐sintering and addition of flow agent, were taken
in the attempt to improve the processability of the original powder feedstock. The
results showed that while the addition of flow agent has more significant effects in
improving the flowability of the powder used, the post sintered parts exhibit
considerable shrinkage and residual porosity that necessitates further investigation. | null | null | null | null | null | null |
['McNulty, Thomas F.', 'Cornejo, Ivan', 'Mohammadi, Farhad', 'Danforth, Stephen C.', 'Safari, Ahmad'] | 2019-02-26T21:00:54Z | 2019-02-26T21:00:54Z | 1998 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/73503', 'http://dx.doi.org/10.26153/tsw/653'] | eng | 1998 International Solid Freeform Fabrication Symposium | Open | ['FDC', 'PZT'] | Development of a Binder Formulation for Fused Deposition of Ceramics | Conference paper | https://repositories.lib.utexas.edu//bitstreams/e548cca4-df05-4856-b3b0-6de8b4ce21f9/download | null | A new binder formulation has been developed for Fused Deposition of Ceramics
(FDC) which consists of commercially-available polymer constituents.. This formulation
was used. in conjunction with lead zirconate titanate (PZT) and hydroxyapatite (HAp)
powders. Adsorption studies were performed to test the effectiveness of several
carboxylic acids and alcohols on the dispersion ofthese powders in the binder system. In
both cases, it was found that stearic acid was most effective as a dispersant for the
ceramic powder / thermoplastic system. After a suitable dispersant was chosen, ceramic
powders were compounded with the binder formulation to yield 55 vol.% ceramic-loaded
materials. The resultant compound was·used to make filament suitable for use in a
modified StratasysTM 3D-Modeler. The filament was well suited for FDC usage, and the
parts made using FDC contained no detectable filament-related defects | null | null | null | null | null | null |
['Wang, Jia-Chang', 'Hitesh, D.'] | 2021-11-18T19:09:02Z | 2021-11-18T19:09:02Z | 2019 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90472', 'http://dx.doi.org/10.26153/tsw/17393'] | eng | 2019 International Solid Freeform Fabrication Symposium | Open | ['additive manufacturing', '3D printing', 'ceramics', 'slurry', '3S ceramics', 'alumina'] | Development of a Circular 3S 3D Printing System to Efficiently Fabricate Alumina Ceramic Products | Conference paper | https://repositories.lib.utexas.edu//bitstreams/1baf0dc7-01ad-4d57-b0b1-fa2f6599bcde/download | University of Texas at Austin | The Solvent based Slurry Stereolithography (3S) system has the capability of fabricating high
quality objects using high performance ceramic (HPC) material. The 3S system is able to fabricate
intrinsic features without supporting structures; while its downsides exhibit consuming lot of time
(30 sec/layer) for fabrication compared to other DLP apparatuses and low efficiency raw material
consumption. A new system named as Circular - 3S (C3S) is developed by adapting the 3S
technology to improve the fabrication process. It consists of multiple DLP and a circular platform
where a paving blade paves the slurry in a circular manner. The demonstrated system has increased
the production rate to 200% with printing speed of 15sec/layer. In this paper, the development of
the C3S system is presented by simultaneously displaying the capabilities and raw material
efficiency of the new C3S system. | null | null | null | null | null | null |
['Kumar, Saripella Surya', 'Stucker, Brent'] | 2020-02-21T15:48:39Z | 2020-02-21T15:48:39Z | 2005 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/80064', 'http://dx.doi.org/10.26153/tsw/7086'] | eng | 2005 International Solid Freeform Fabrication Symposium | Open | Intermetallic | Development of a Co-Cr-Mo to Tantalum Transition using LENS for Orthopedic Applications | Conference paper | https://repositories.lib.utexas.edu//bitstreams/a9594083-498c-4bc0-8868-af20584c8f93/download | null | Biomedical implant material research using additive manufacturing is a popular field of
study. Many potential material combinations exist which, if implemented properly, could
have a significantly positive effect on implant life and functionality. One material
combination of interest is attaching porous Ta bone ingrowth material to a CoCrMo
corrosion and wear resistant bearing surface. An investigation of the ability of the LENS
process to join Ta to CoCrMo was undertaken. Direct joining of CoCrMo to Ta was
known to be problematic, and thus transitional layers of other biomedically-compatible
materials were investigated. It was determined that a transitional layer of zirconium
appeared to be the best transitional material for this application due to its excellent
biocompatibility, followed by stainless steel, with a lesser biocompatibility but better
adhesive properties. | null | null | null | null | null | null |
['Ma, Zhichao', 'Munguia, Javier', 'Hyde, Philip', 'Drinnan, Michael'] | 2021-11-09T18:48:07Z | 2021-11-09T18:48:07Z | 2018 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90115', 'http://dx.doi.org/10.26153/tsw/17036'] | eng | 2018 International Solid Freeform Fabrication Symposium | Open | ['reverse engineering', 'additive manufacturing', 'CPAP mask', 'continuous positive airway pressure', 'obstructive sleep apnoea', 'customization'] | Development of a Customized CPAP Mask Using Reverse Engineering and Additive Manufacturing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/c9636681-4afe-4002-a644-f4f7457d6544/download | University of Texas at Austin | Continuous positive airway pressure (CPAP) therapy has been widely used to treat moderate
and/or severe Obstructive Sleep Apnoea (OSA) syndrome since its invention. However, CPAP
mask interface induced side effects, such as air leak, noise, discomfort and facial skin problem,
considerably affect the overall effectiveness of CPAP treatment. Conventional CPAP masks
designed with averaged individual facial characteristics have standard configuration and
limited material selection. Mask size ranges are limited, only coming with small, medium, and
large. The material used for the mask interface fabrication is mainly silicone-based material.
Besides the limitations on mask configuration and material, there are no comprehensive mask
selection templates and guidance offered by CPAP mask suppliers. Individuals have
completely different physical characteristics, such as face topology, skin sensitivity, the
severity of OSA syndrome, sleep habit and breathing pattern. Therefore, conventional masks
cannot properly fit individual’s physical characteristics. Customization of CPAP mask using
Reverse Engineering and Additive Manufacturing techniques offers the great potential to
minimize the CPAP mask interface induced side effects. | null | null | null | null | null | null |
['Boivie, K.', 'Sørby, K.', 'Brøtan, V.', 'Ystgaard, P.'] | 2021-10-04T21:03:35Z | 2021-10-04T21:03:35Z | 8/17/11 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88345', 'http://dx.doi.org/10.26153/tsw/15284'] | eng | 2011 International Solid Freeform Fabrication Symposium | Open | ['Additive Manufacturing', 'injection molding', 'tool production', 'insert production', 'CNC milling', 'hybrid process'] | Development of a Hybrid Manufacturing Cell; Integration of Additive Manufacturing with CNC Machining | Conference paper | https://repositories.lib.utexas.edu//bitstreams/8ac15a0b-0f02-4c1e-b51a-419d1ae4e37b/download | University of Texas at Austin | The application of Additive Manufacturing (AM) for production of injection molding
tools and tooling inserts enables significant improvements in regards to, for example, product
quality and cycle times. However, the AM based production of tools and inserts is most often
far from being rapid and the inserts are usually considerably more expensive than
conventionally produced. A combination of AM with CNC milling in a hybrid process route
allows for the application of each process to the production of the section of the product
geometry for which it is most advantageous. However, this approach also multiplies the
number of process steps and therefore also the limiting factors and possible causes of failure.
This paper describes the development of a Hybrid Manufacturing cell by integration of AM
with conventional CNC milling in a robust, streamlined production sequence. | null | null | null | null | null | null |
['Hill, Leon', 'Sparks, Todd', 'Liou, Frank'] | 2021-11-04T18:20:02Z | 2021-11-04T18:20:02Z | 2017 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/89996', 'http://dx.doi.org/10.26153/16917'] | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['metal parts', 'CNC-level precision', 'hybrid manufacturing', 'research & development', 'R&D'] | Development of a Hybrid Manufacturing Process for Precision Metal Parts | Conference paper | https://repositories.lib.utexas.edu//bitstreams/230c1726-7ab1-4ce2-b57c-5ded25f5131e/download | University of Texas at Austin | This paper summarizes the research and development of a hybrid manufacturing process to
produce fully dense metal parts with CNC-level precision. High performance metals, such
as titanium alloys, nickel superalloys, tool steels, stainless steels, etc. can benefit from this
process. Coupling the additive and the subtractive processes into a multi-axis workstation,
the hybrid process, can produce and repair metal parts with accuracy. The surface quality
of the final product is similar to the industrial milling capability. To achieve such a system,
issues of the metal deposition process and the automated process planning of the hybrid
manufacturing process will be discussed. | null | null | null | null | null | null |
['Barua, Shyam', 'Sparks, Todd', 'Liou, Frank'] | 2021-09-30T13:16:00Z | 2021-09-30T13:16:00Z | 2010 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88229', 'http://dx.doi.org/10.26153/tsw/15170'] | eng | 2010 International Solid Freeform Fabrication Symposium | Open | ['laser metal deposition process', 'low-cost', 'vision system', 'melt pool size'] | Development of a Low Cost Imaging System for a Laser Metal Deposition Process | Conference paper | https://repositories.lib.utexas.edu//bitstreams/7020f0df-0e34-4c3e-8bdd-9caa988492a6/download | University of Texas at Austin | The size of the melt pool created by the laser is one of the most important quality characteristic
in a laser metal deposition process. This paper discusses the development of a low-cost vision
system to automatically determine the size of the melt pool for in-process control. To cope
with the intense infrared signal from the laser and melt pool, external ultraviolet illumination
is paired with narrow bandpass filters on a usb microscope to achieve a clear image of the melt
pool. The sensitivity of the melt pool to changes in system parameters and various substrate
materials are also evaluated. | null | null | null | null | null | null |
['Hammond, C.', 'Greenstreet, J.', 'Gomez, W.', 'Dang, R.', 'Tate, J.'] | 2023-03-29T16:22:34Z | 2023-03-29T16:22:34Z | 2022 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/117678', 'http://dx.doi.org/10.26153/tsw/44557'] | eng | 2022 International Solid Freeform Fabrication Symposium | Open | SLA resin | Development of a Low Thermal Expansion Sla Resin for Nickel Plating Applications | Conference paper | https://repositories.lib.utexas.edu//bitstreams/bd18c7fb-6863-4697-8893-ed9ec969f3f7/download | null | Stereolithography additive manufacturing is a method of producing parts by stacking layers
of a photopolymer resin cured by exposure to UV light . This method of additive manufacturing
gives great resolution, but often lacks the material properties of other techniques. One method to
increase part performance is the addition of a thin nickel plating to increase strength, heat
deflection, and chemical resistance. No solution has been proposed for using nickel-coated parts
in harsh environments where the large difference in thermal expansion rates between the nickel
plating and base resin cause internal stresses to form. The excellent chemical resistance of the
nickel plating would also allow these parts to be used in high-temperature, oxygen-rich
environments such as those presented in life support systems. Through the development of a high-
performance nanocomposite SLA resin, we hope to achieve parts with good mechanical properties
and a CTE similar to nickel. | null | null | null | null | null | null |
['Song, Xuan', 'Pan, Yayue', 'Chen, Yong'] | 2021-10-07T18:21:04Z | 2021-10-07T18:21:04Z | 2013 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88499', 'http://dx.doi.org/10.26153/tsw/15433'] | eng | 2013 International Solid Freeform Fabrication Symposium | Open | ['additive manufacturing', 'multi-direction', 'parallel kinematic machine', 'fused deposition modeling', 'building-around-inserts'] | Development of a Low-Cost Parallel Kinematic Machine for Multi-Directional Additive Manufacturing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/ce96c745-5475-4880-b1ad-b58807f89b39/download | University of Texas at Austin | Most additive manufacturing (AM) processes are layer-based with three linear motions in the X, Y and Z
axes. However, there are drawbacks associated with such limited motions, e.g. non-conformal material
properties, stair-stepping effect, and limitations on building-around-inserts. Such drawbacks will limit
additive manufacturing to be used in more general applications. To enable 6-axis motions between a tool
and a work piece, we investigate a Stewart mechanism and developed a low-cost prototype system for
multi-directional additive manufacturing processes such as the Fused Deposition Modeling (FDM) and
CNC Accumulation. The technical challenges in developing such an AM system are discussed including
the hardware design, motion planning and modeling, platform constraint checking, tool motion simulation,
and platform calibration. Several test cases are performed to illustrate the capability of the developed
multi-directional additive manufacturing system. | null | null | null | null | null | null |
['Sparks, Todd', 'Tang, Lie', 'Liou, Frank'] | 2021-09-28T19:02:57Z | 2021-09-28T19:02:57Z | 2009-09 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88155', 'http://dx.doi.org/10.26153/tsw/15096'] | eng | 2009 International Solid Freeform Fabrication Symposium | Open | ['vision system', 'melt pool tracking', 'laser metal deposition', 'temperature feedback control system'] | Development of a Melt Pool Tracking Vision System for Laser Deposition | Conference paper | https://repositories.lib.utexas.edu//bitstreams/5dcadaa9-4c4b-433f-b0a5-be518fb4e1ad/download | University of Texas at Austin | This paper chronicles the development of a vision system for tracking melt pool morphology in the laser metal deposition process. This development is to augment an existing
temperature feedback control system. Monitoring both the temperature and shape of the
melt pool is necessary because of the effects of local geometry on the cooling rate at the melt
pool. Temperature feedback alone cannot accommodate this effect without complex process
planning. The vision system’s hardware, software, and integration into the laser deposition
system’s controller is detailed in this paper. Preliminary testing and the effects on deposition
quality is also discussed. | null | null | null | null | null | null |
['Lammers, S.', 'Lieneke, T.', 'Zimmer, D.'] | 2021-12-01T22:04:28Z | 2021-12-01T22:04:28Z | 2021 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90631', 'http://dx.doi.org/10.26153/tsw/17550'] | eng | 2021 International Solid Freeform Fabrication Symposium | Open | ['support structures', 'process parameters', 'design guidelines', 'laser powder bed fusion'] | Development of a Method to Derive Design Guidelines for Production-suitable Support Structures in Metal Laser Powder Bed Fusion | Conference paper | https://repositories.lib.utexas.edu//bitstreams/90af2513-87c7-445f-87c8-0b725299aeff/download | University of Texas at Austin | Solid support structures in metal laser powder bed fusion have a significant influence on the economic
applicability, component quality and process stability and represent a central challenge for widespread
industrial use. As the connection of the components to the building platform by supports is essential,
the negative effects must be minimized at the same time as the supporting effect is optimized. Within the
scope of this study, a standardized method is developed that allows the investigation of several support
structures and parameters with regard to their influence on the target variables: component quality, process
efficiency and stability. In addition to the proof of general suitability, the applicability is investigated
using so-called standard elements. Based on the experimental results, design guidelines are derived, which
will serve as a basis for decision-making during the selection of support structure for an individual
application. | null | null | null | null | null | null |
['Zhou, Chi', 'Chen, Yong', 'Yang, Zhigang', 'Khoshnevis, Behrokh'] | 2021-10-04T20:26:44Z | 2021-10-04T20:26:44Z | 2011 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88339', 'http://dx.doi.org/10.26153/tsw/15278'] | eng | 2011 International Solid Freeform Fabrication Symposium | Open | ['additive manufacturing', 'multi-material fabrication', 'bottom-up projection', 'part separation'] | Development of a Multi-Material Mask-Image-Projection-Based Stereolithography for the Fabrication of Digital Materials | Conference paper | https://repositories.lib.utexas.edu//bitstreams/563335aa-9fb8-4bb7-961f-f9bd8662c63e/download | University of Texas at Austin | Digital materials such as the ones shown by Objet’s Connex family demonstrate that a new material with
desired characteristics can be achieved by combining two different base materials with various
concentrations and structures. We investigate the feasibility of using additive manufacturing processes
based on digital mask projection in the fabrication of such digital materials. A multi-material mask-image-projection-based Stereolithography process has been developed. The related challenges on the
development of such a process are identified. Our approaches to address such challenges are presented. A
testbed has been developed to fabricate component with designed digital materials. Experimental results
illustrate desired material properties can be achieved based on the developed process. Several multi-material designs have been produced to highlight the capability of this promising technology for
fabricating three-dimensional, multi-material objects with spatial control over placement of both material
and structure. The limitations and challenges for future development have also been identified. | null | null | null | null | null | null |
['Jalui, Sagar S.', 'Zargar, Seyed Hossein', 'Moroney, Sheila', 'Putz, Marcus', 'Taylor, Mychal', 'Hatch, Serah', 'Manogharan, Guha'] | 2023-02-10T14:11:20Z | 2023-02-10T14:11:20Z | 2022 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/117450', 'http://dx.doi.org/10.26153/tsw/44331'] | eng | 2022 International Solid Freeform Fabrication Symposium | Open | ['Conformal printing', 'test artifact', 'dual-DfAM', 'material extrusion', 'parametric design'] | Development of a Novel Test Artefact for Conformal Material Extrusion Printing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/77f485f7-b2d2-4592-934b-0562d734f030/download | null | Additive manufacturing (AM) allows for free complexity. However, the layer-by-layer
manufacturing method traditionally relies on a G-code input to the machine, representing 2D
planar slices of each layer, which eventually combines to represent the net-shape 3D geometry.
Through modification of existing slicer software, thus modifying the G-code input to the machine,
non-planar (conformal) shells can be generated on top of a traditional planar scaffolding. The
objective of this work is to design a novel test artifact to aid in the creation of design rules and to
identify machine limitations for conformal printing. With the use of non-conventional design
features using trigonometric (sine) surfaces, this test artifact would allow for deeper insights into
the print quality of organic shapes made possible using a commercial, low-cost, material extrusion
3D printer. It would also enable the creation of design rules for conformal printing to push forward
the true dual-Design for Additive Manufacturing (dual-DfAM) potential. | null | null | null | null | null | null |
['Liou, F.W.', 'Zhang, J.', 'Agarwal, S.', 'Laeng, J.', 'Stewart, J.'] | 2019-09-23T16:36:40Z | 2019-09-23T16:36:40Z | 2000 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/75959', 'http://dx.doi.org/10.26153/tsw/3058'] | eng | 2000 International Solid Freeform Fabrication Symposium | Open | Precision | Development of A Precision Rapid Metal Forming Process 362 | Conference paper | https://repositories.lib.utexas.edu//bitstreams/b8a940ae-8621-4465-885f-579a9d9b6b77/download | null | This paper presents the important issues pertaining to the development of a precision rapid metal forming process. A five-axis configuration provides a flexible building capability to produce free-form fabrication capability. The laser cladding process is able to produce functional mechanical parts and machining capability is able to produce industrial grade surface quality. A machine configuration that combines the laser cladding and CNC machining processes is presented. The related parameters and components are discussed. | This research was supported by the National Science Foundation Grant Number DMI-9871185, Missouri Research Board, and a grant from the Missouri Department of Economic Development through the MRTC grant. | null | null | null | null | null |
['Watson, J.K.', 'Taminger, K.M.', 'Hafley, R.A.', 'Petersen, D.D.'] | 2019-10-24T18:22:37Z | 2019-10-24T18:22:37Z | 2002 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/77418', 'http://dx.doi.org/10.26153/tsw/4507'] | eng | 2002 International Solid Freeform Fabrication Symposium | Open | Fabrication | Development of a Prototype Low-Voltage Electron Beam Freeform Fabrication System | Conference paper | https://repositories.lib.utexas.edu//bitstreams/ff5261cb-b479-4ae0-bc75-e74f43141f71/download | null | NASA’s Langley Research Center and Johnson Space Center are developing a solid
freeform fabrication system utilizing an electron beam energy source and wire feedstock. This
system will serve as a testbed for exploring the influence of gravitational acceleration on the
deposition process and will be a simplified prototype for future systems that may be deployed
during long-duration space missions for assembly, fabrication, and production of structural and
mechanical replacement components. Critical attributes for this system are compactness,
minimal mass, efficiency in use of feedstock material, energy use efficiency, and safety. The use
of a low-voltage (<15kV) electron beam energy source will reduce radiation so that massive
shielding is not required to protect adjacent personnel. Feedstock efficiency will be optimized
by use of wire, and energy use efficiency will be achieved by use of the electron beam energy
source. This system will be evaluated in a microgravity environment using the NASA KC-135A
aircraft. | null | null | null | null | null | null |
['Stephen, A.O.', 'Dalgarno, K.W.', 'Munguia, J.'] | 2021-10-07T15:25:32Z | 2021-10-07T15:25:32Z | 2013 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88480', 'http://dx.doi.org/10.26153/tsw/15414'] | eng | 2013 International Solid Freeform Fabrication Symposium | Open | ['selective laser sintering', 'quality system', 'process monitoring', 'polymer based'] | Development of a Quality System for Polymer Based Selective Laser Sintering Process | Conference paper | https://repositories.lib.utexas.edu//bitstreams/24856157-d8b7-4ffb-8677-bdb91a0ac07c/download | University of Texas at Austin | The aim of this study is to develop a quality system for selective laser sintering, based
on defining a minimum set of tests to qualify a build. MFI, impact and flexural tests were
assessed, along with density, dimensional measurements and SEM. A benchmark part was
designed for manufacture to track changes in key parameters from build to build, and tests on
this validated against ISO standards. It is concluded that a combination of measures of
flexural modulus, density and impact strength can be used for process monitoring and to infer
the quality of a build in SLS process. | null | null | null | null | null | null |
['Birmingham, B.R.', 'Tompkins, J.V.', 'Zong, G.', 'Marcus, H.L.'] | 2018-04-19T17:39:04Z | 2018-04-19T17:39:04Z | 1992 | Mechanical Engineering | doi:10.15781/T25H7CB2F | http://hdl.handle.net/2152/64392 | eng | 1992 International Solid Freeform Fabrication Symposium | Open | ['Center for Materials Science and Engineering', 'SLS', 'SLRS'] | Development of a Selective Laser Reaction Sintering Workstation | Conference paper | https://repositories.lib.utexas.edu//bitstreams/bd929ae1-5d22-4125-b243-1ad56fc5bd4f/download | null | The purpose of this paper is to describe the design and operation
of a Selective Laser Reaction Sintering workstation developed at The
University of Texas. The workstation allows the study of solid freeform
fabrication of reaction sintered materials on a research scale. The
mechanical and control systems of the workstation are detailed, and
Selective Laser Reaction Sintering as a technique is discussed including
example material systems that are currently under study. | null | null | null | null | null | null |
['Forderhase, Paul', 'McAlea, Kevin', 'Booth, Richard'] | 2018-11-02T16:21:51Z | 2018-11-02T16:21:51Z | 1995 | Mechanical Engineering | doi:10.15781/T2S757482 | http://hdl.handle.net/2152/69336 | eng | 1995 International Solid Freeform Fabrication Symposium | Open | ['polymer industry', 'SLS', 'fully-dense functional prototypes'] | The Development of a SLS Composite Material | Conference paper | https://repositories.lib.utexas.edu//bitstreams/e56ab381-7c0f-440b-acc4-ce703aa8c9ba/download | null | The development of a commercial SLS nylon-based composite material (LNC 7000) is
described. Nylon composite candidate systems with different volume fractions of a
number of glass fiber and glass bead reinforcements were screened. It was found that fully
dense SLS parts with excellent mechanical properties could be made from a number of
reinforced nylon materials. An optimized material containing 29 volume percent 35 Ilm
diameter glass beads was selected based on the processing behavior and mechanical
properties of the candidate systems. The performance of this optimized material is
described. In addition, complementary aspects of the composite nylon and unreinforced
nylon materials (LN 4010 and LNF 5000) are discussed. | null | null | null | null | null | null |
['Quinn, Paul', "O'Halloran, Sinead", 'Ryan, Catriona', 'Pamell, Andrew', 'Lawlor, Jim', 'Raghavendra, Ramesh'] | 2021-11-18T17:58:57Z | 2021-11-18T17:58:57Z | 2019 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90448', 'http://dx.doi.org/10.26153/tsw/17369'] | eng | 2019 International Solid Freeform Fabrication Symposium | Open | ['metal additive manufacturing', 'powder bed fusion', 'in-situ process monitoring', 'defect detection'] | Development of a Standalone In-Situ Monitoring System for Defect Detection in the Direct Metal Laser Sintering Process | Conference paper | https://repositories.lib.utexas.edu//bitstreams/94d10d0f-99fd-4ce0-96f4-23917f5b6b59/download | University of Texas at Austin | Direct metal laser sintering (DMLS) is a powder bed fusion (PBF) additive manufacturing process
commonly used within the medical device and aerospace industries where regulations drive the requirement for
stringent quality control. Using in-situ monitoring, the identification of defects, as well as the geometric and
dimensional measurement of the layers throughout the build allows for greater quality control, as well as a
reduction in the requirement for ex-situ measurement. A standalone monitoring system for the EOS M280 is
presented in this research, allowing for the build process to be monitored layer-by-layer. The system images the
build area after powder deposition and after laser exposure allowing for the identification of inefficiencies in both
the powder deposition and the laser exposure. The system has proven to be capable to identify in build defects
and work is ongoing to develop an automated program to identify these defects and notify the operator in real
time. | null | null | null | null | null | null |
['Yang, Chen-Wei', 'Kuan, Alexander', 'Li, Sheng-Yen', 'Lu, Yan', 'Kim, Jaehyuk', 'Cheng, Fan-Tien', 'Yang, Haw-Ching'] | 2024-03-27T16:12:44Z | 2024-03-27T16:12:44Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124504', 'https://doi.org/10.26153/tsw/51112'] | en | 2023 International Solid Freeform Fabrication Symposium | Open | ['additive manufacturing', 'data integration testbench', 'NIST'] | Development of a Testbench for Additive Manufacturing Data Integration, Management, and Analytics | Conference paper | https://repositories.lib.utexas.edu//bitstreams/c0d044f4-ec29-4c42-a1c6-753c018fbdac/download | University of Texas at Austin | The NIST Additive Manufacturing (AM) Data Integration Testbench is a platform
designed to evaluate data models, communication methods, and data analytics for AM
industrialization. This paper describes a reference framework for AM data integration, named
AMIF, and the design of the testbench based on AM Integration Framework (AMIF) for testing
the integration of in-process data acquisition, real-time feature extraction, process control, and
predictive models under a data management system. A specification of this testbench is developed
to manage and stream voluminous data captured by high-speed cameras and performing data
analytics using common information models and functional interfaces. The integration of the data,
models, and computer tools sends operational decisions to an AM machine in real time. On top of
the real-time control functions, AM data integration with MES and ERP systems is also included
using a high-performance data warehouse for long-term data archiving and metadata management.
The architecture of this testbench is illustrated in this work. AMIF can guide AM practitioners and
system integrators to build their integrated AM manufacturing systems for production. The NIST
AM testbench’s plug-and-play features allow both internal and external researchers and developers
to assess the effectiveness of their individual data models, data analytics, and decision-making
algorithms on the systems engineering level. | null | null | null | null | null | null |
['Obielodan, John', 'Helman, Joshua', 'Grumbles, Andrew'] | 2021-11-09T20:38:35Z | 2021-11-09T20:38:35Z | 2018 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90161', 'http://dx.doi.org/10.26153/tsw/17082'] | eng | 2018 International Solid Freeform Fabrication Symposium | Open | ['3D printing', 'biocomposite', 'thermoplastics', 'polylactic acid', 'PLA', 'organosolv lignin', 'filament extrusion'] | Development of a Thermoplastic Biocomposite for 3D Printing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/99056ed5-8030-429e-b528-cae6945553a4/download | University of Texas at Austin | Organosolv lignin, a natural cross-linked phenolic wood polymer is a by-product of the
pulping process in the paper industry. It is a renewable organic natural product with potential
application in many areas. It has attractive properties that make it a potential candidate for
fabricating useful parts using 3D printing. Also, polylactic acid (PLA), a biodegradable
thermoplastic derived from renewable sources is widely used in 3D printing polymer parts. This
work seeks to study the technical viability of extruding different blends of PLA and organosolv
lignin into filaments for 3D printing useful objects. Filament extrusions using different blends
were evaluated. Also, the mechanical properties of printed test samples are presented. Viable
blends of the biocomposite for 3D printing has the potential to provide an added-value to lignin
for expanded use in many applications. | null | null | null | null | null | null |
['Eschner, N.', 'Weiser, L.', 'Häfner, B.', 'Lanza, G.'] | 2021-11-15T21:56:12Z | 2021-11-15T21:56:12Z | 2018 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90284', 'http://dx.doi.org/10.26153/tsw/17205'] | eng | 2018 International Solid Freeform Fabrication Symposium | Open | ['acoustic process monitoring', 'in-process integration', 'acoustic measurement', 'selective laser melting', 'design of experiments'] | Development of an Acoustic Process Monitoring System for Selective Laser Melting (SLM) | Conference paper | https://repositories.lib.utexas.edu//bitstreams/2350ce7e-dbc9-41bd-a79d-31481de65a98/download | University of Texas at Austin | The current selective laser melting (SLM) process lacks both process quality and reproducibility. Recent
research focuses on the integration of optical measuring technology, but acoustic sensors also seem promising.
Initial results on acoustic methods show their suitability. The further processing of the data still shows difficulties,
mostly due to the high sample rate. In this work a concept for an acoustic process monitoring system is developed
and integrated into the process. First results show its capability to distinguish different process qualities.
For this purpose, various configurations for in-process integration of acoustic measurement techniques
are discussed and evaluated. The most promising structure-borne sound concept is integrated and tested in a test
bed. In a Design of Experiments for specific parameter selection, cubes with different process qualities are
produced, and the acoustic signatures are evaluated. For a first prove of concepts a Neuronal Network is trained
to classify three different laser classes. Therefore, different NN topologies were tested and the best-found solution
had a precision of more than 90%. | null | null | null | null | null | null |
['Smith, P.C.', 'Rennie, A.E.W.'] | 2021-09-23T22:21:00Z | 2021-09-23T22:21:00Z | 9/10/08 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88038', 'http://dx.doi.org/10.26153/tsw/14979'] | eng | 2008 International Solid Freeform Fabrication Symposium | Open | ['Additive Layer Manufacturing', 'design for rapid manufacture', 'selection tool', 'creative industry'] | Development of an Additive Layer Manufacturing (ALM) Selection Tool for Direct Manufacture of Products | Conference paper | https://repositories.lib.utexas.edu//bitstreams/e4f1074e-5800-4213-be1a-44f692f0992c/download | null | Advancements in Additive Layer Manufacturing (ALM) technology and a broader knowledge
base of process and material capabilities make ALM increasingly, a more valid manufacturing
option.
Small creative industry and industrial designers in the UK, as well as experienced engineers,
can benefit from the freedom from design, manufacture and distribution constraints that ALM
technology offers, yet they are unaware of the opportunities available.
This paper present a method for selecting an ALM technology as a manufacturing method,
based on a part specification, as an ALM selection tool. Selecting appropriate processes,
materials and giving design for rapid manufacture advice are part of the recommendations offered
from this ALM selection tool. | null | null | null | null | null | null |
['Inamdar, Asim', 'Magana, Marco', 'Medina, Frank', 'Grajeda, Yinko', 'Wicker, Ryan'] | 2020-03-05T19:33:55Z | 2020-03-05T19:33:55Z | 2006 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/80146', 'http://dx.doi.org/10.26153/tsw/7167'] | eng | 2006 International Solid Freeform Fabrication Symposium | Open | Multiple Material Stereolithography | Development of an Automated Multiple Material Stereolithography Machine | Conference paper | https://repositories.lib.utexas.edu//bitstreams/b7f27fc0-a755-4931-8dbe-0a910a4714b3/download | null | An automated Multiple Material Stereolithography (MMSL) machine was developed by
integrating components of a 3D Systems 250/50 stereolithography (SL) machine in a separate
stand-alone system and adapting them to function with additional components required for
MMSL operation. We previously reported retrofitting a 250/50 SL machine with multiple vats
to accommodate multiple material fabrication for building a wide variety of multi-material
models (Wicker et al., 2004). In the MMSL retrofit, spatial constraints limited the multiple vats
located circumferentially on a vertical rotating vat carousel to cross-sectional areas of
approximately 4.5-inches by 4.5-inches. The limited build size of the retrofitted 250/50
motivated the full development of a new system with multiple material build capabilities
comparable to the build envelope of the original 250/50 machine. The new MMSL machine
required fabrication of a large system frame, incorporating various 250/50 components and
software, and adding a variety of new components and software. By using many existing
components and software, the previous engineering development of 3D Systems could be
directly applied to this new technology. Components that were transferred from an existing
250/50 to the MMSL machine included the complete optical system (including the optics plate
with laser, mirrors, beam expander, scanning mirrors, and focusing lens), the rim assembly
(including the laser beam profilers), the associated controllers (computer system, scanning mirror
controller, power supply-vat controller) and the wiring harness. In addition to the new frame, the
MMSL machine required the development of a new rotating vat carousel system, platform
assembly, multi-pump filling/leveling system, and a custom LabVIEW® control system to
provide automated control over the MMSL process. The overall operation of the MMSL system
was managed using the LabVIEW® program, which also included controlling a new vat leveling
system and new linear and rotational stages, while the 3D Systems software (Buildstation 4.0)
was retained for controlling the laser scanning process. As a demonstration of MMSL
technology, simple multi material parts were fabricated with vertically and horizontally oriented
interfaces. The fully functional MMSL system offers enormous potential for fabricating a wide
variety of multiple material functional devices. | null | null | null | null | null | null |
['Deppe, G.', 'Lindemann, C.', 'Koch, R.'] | 2021-10-21T20:28:49Z | 2021-10-21T20:28:49Z | 2015 | Mechanical Engineering | null | https://hdl.handle.net/2152/89439 | eng | 2015 International Solid Freeform Fabrication Symposium | Open | ['additive manufacturing', 'MRO workflows', 'aerospace'] | Development of an Economic Decision Support for the Application of Additive Manufacture in Aerospace | Conference paper | https://repositories.lib.utexas.edu//bitstreams/428b9cb8-7e52-4ef8-8bbd-e398eafa5024/download | University of Texas at Austin | Additive Manufacturing offers a high potential in aerospace industry due to its freedom of
design and the ability to manufacture complex and lightweight parts. The low number of
units, high quality standards and fast response time are special challenges that have to be met
especially in the Maintenance, Repair and Overhaul sector. Thus, companies have to decide at
which point it is economic to apply Additive Manufacturing. However, companies lack
experience on this new technology. This is why a tool is required that takes into account the
above mentioned crucial points and supports the decision process. The paper analyzes
aviation’s characteristics with regard to Additive Manufacturing. The structure of current
MRO repair workflows is investigated to identify a feasible application for Additive
Manufacturing. Additionally the supply chain will be examined to indicate the benefit which
the technology can generate in this highly demanding field. The findings are integrated into a
methodology that supports the decision whether to apply Additive Manufacturing on the basis
of costs, time and quality. | null | null | null | null | null | null |
['Hilton, Zachary T.', 'Newkirk, Joseph W.', "O'Malley, Ronald J."] | 2021-11-10T22:37:26Z | 2021-11-10T22:37:26Z | 2018 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90195', 'http://dx.doi.org/10.26153/tsw/17116'] | eng | 2018 International Solid Freeform Fabrication Symposium | Open | ['engineering diagram', 'stainless steel', 'stainless steel alloys', 'additive manufacturing'] | Development of an Engineering Diagram for Additively Manufactured Austenitic Stainless Steel Alloys | Conference paper | https://repositories.lib.utexas.edu//bitstreams/9aa05542-8660-473a-8388-e485d44231b4/download | University of Texas at Austin | Austenitic stainless steels are the most widely applied types of stainless steels, due to their good
weldability and high corrosion resistance. A number of engineering diagrams exist for the
purpose of providing insight into the behavior of these steels. Examples of these diagrams are
constitution diagrams (aka Schaeffler Diagrams) which are used to approximate the solidification
path of the alloy and the amount of retained ferrite in the solidified matrix. Other diagrams are
the Suutala diagram, which approximates cracking susceptibility, and microstructural maps,
which predict the solidification path by varying a processing parameter, such as cooling rate. By
combining these diagrams, a much more concrete conclusion can be made as to the behavior of a
particular steel. This approach could be used to determine differences in behaviors between two
different compositions. The developed diagram would be intended for use with rapid
solidification phenomena as observed in the selective laser melting process. | null | null | null | null | null | null |
['Lohn, Johannes', 'Kummert, Christina', 'Schmid, Hans-Joachim'] | 2021-11-02T18:36:19Z | 2021-11-02T18:36:19Z | 2017 | Mechanical Engineering | null | https://hdl.handle.net/2152/89863 | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['laser sintering machine', 'laser sintering', 'processing'] | Development of an Experimental Laser Sintering Machine to Process New Materials Like Nylon 6 | Conference paper | https://repositories.lib.utexas.edu//bitstreams/74448d92-87e1-402d-b611-5d6db665ab57/download | University of Texas at Austin | Selective Laser Sintering (SLS) is an Additive Manufacturing technology which allows the
production of functional polymer parts. Conventionally, Nylon 12 (PA 12), Polyamide 11 (PA 11),
glass- or aluminum filled materials are used. Those materials do not always meet the requirements
for direct production of serial parts by laser sintering. For the so called “Direct Manufacturing” of
high quality, functional parts, the laser sintering process needs to be further developed and the
choice of materials and needs to be expanded.
During this research, a laser sintering machine for material qualification has been built up. The
advantages are an optimized software solution, an innovative optical system with an adjustable
laserspot, an alternative powder coating system and an improved temperature control.
The functionality of the test equipment is proved with the standard material PA2200 and the new
laser-sintering-material, Polyamide 6X (PA6X) is investigated. The required process parameters
for processing PA6X are derived and the mechanical properties are determined by tensile tests. | null | null | null | null | null | null |
['Uhlmann, Eckart', 'Krohmer, Erwin', 'Hohlstein, Felix', 'Reimers, Walter'] | 2021-11-04T13:42:12Z | 2021-11-04T13:42:12Z | 2017 | Mechanical Engineering | null | https://hdl.handle.net/2152/89957 | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['strain evaluation', 'in situ', 'residual stress', 'selective laser melting', 'experimental test setup'] | Development of an Experimental Test Setup for In Situ Strain Evaluation During Selective Laser Melting | Conference paper | https://repositories.lib.utexas.edu//bitstreams/41cce3aa-8fe7-4878-ba2f-bef308030c15/download | University of Texas at Austin | Selective Laser Melting (SLM) is an Additive Manufacturing (AM) process which still
underlies a lack of profound process understanding. This becomes obvious when deformation and
crack formation can be observed in SLM parts due to residual stresses. Controlling residual
stresses is therefore an important topic of recent research in AM of metals. In order to minimize
residual stresses further knowledge considering their cause and physical correlations of process
parameters needs to be generated. In this paper an approach of measuring strains layer by layer
during the SLM process by means of in situ X-ray diffraction is presented. For this purpose an
experimental test setup is being constructed at the Technische Universität Berlin. The system
requirements and operating principles are discussed in this paper. Furthermore, details of the
current progress of the construction are highlighted. | null | null | null | null | null | null |
['Ma, Guohua', 'Crawford, Richard H.'] | 2019-10-24T18:02:58Z | 2019-10-24T18:02:58Z | 2002 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/77412', 'http://dx.doi.org/10.26153/tsw/4501'] | eng | 2002 International Solid Freeform Fabrication Symposium | Open | Integrated Graphical | The Development of an Integrated Graphical SLS Process Control Interface | Conference paper | https://repositories.lib.utexas.edu//bitstreams/7d118629-8c0d-4ddf-9711-9438f83001bd/download | null | This paper presents the systematic development of a man/machine interface for Selective
Laser Sintering. The interface developed integrates geometry design, process data/code generation, power
control and communication in a graphical environment. The objective of this interface is to
provide high flexibility and robustness to researchers to meet their special needs. For example,
the user can generate laser power profiles of any shape, or control the laser power by PWM or an
analog voltage. The control code for the machine is automatically generated with minimum
human input. Currently the interface is limited to use on a single layer machine, but can be
easily modified for multi-layer machines. LabVIEW™ is employed as the developing platform. | null | null | null | null | null | null |
['Cunico, Marlon Wesley Machado', 'Cavalheiro, Patrick Medeiros', 'de Carvalho, Jonas'] | 2021-11-04T18:28:15Z | 2021-11-04T18:28:15Z | 2017 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/89999', 'http://dx.doi.org/10.26153/16920'] | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['additive manufacturing', 'smoothing process', 'dimensional evaluation'] | Development of Automatic Smoothing Station Based on Solvent Vapour Attack for Low Cost 3D Printers | Conference paper | https://repositories.lib.utexas.edu//bitstreams/9cc0f080-e263-4d42-be2b-9c9300f5af09/download | University of Texas at Austin | Along the last years, 3d printing has been playing a new and important role in several market
segments. As consequence, finishing methods have been developed and applied in order to improve
surface roughness and mechanical strength. One of these methods is the solvent vapour attack.
Nonetheless, this process is still manual and might lead to object deformation or structural
damages. For that reason, the main goal of this work is to present a new approach that was
implemented in automatic smoothing station. In this new approach, a close-looping control system
identifies the vapour attack level in addition to controlling drying time and number of times that
cycle is repeated. By the end, this proposal was identified to advances in 3d printing field, being a
next step for domestic and distributed manufacturing. | null | null | null | null | null | null |
['Fuesting, T.', 'Brown, L.', 'Das, S.', 'Harlan, N.', 'Lee, G.', 'Beaman, J.J.', 'Bourell, D.L.', 'Barlow, J.W.', 'Sargent, K.'] | 2018-11-08T19:59:10Z | 2018-11-08T19:59:10Z | 1996 | Mechanical Engineering | doi:10.15781/T2BZ61T84 | http://hdl.handle.net/2152/69918 | eng | 1996 International Solid Freeform Fabrication Symposium | Open | ['shrinkage', 'compositions', 'volumetric comparison'] | Development of Direct SLS Processing for Production of Cermet Composite Turbine Sealing Components- Part II | Conference paper | https://repositories.lib.utexas.edu//bitstreams/15e5f7a7-9073-4f67-a701-54f5c9782033/download | null | null | null | null | null | null | null | null |
['Oakes, Thomas', 'Kulkarni, Parimal', 'Landers, Robert G.', 'Leu, Ming C.'] | 2021-09-28T19:25:51Z | 2021-09-28T19:25:51Z | 2009-09 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88160', 'http://dx.doi.org/10.26153/tsw/15101'] | eng | 2009 International Solid Freeform Fabrication Symposium | Open | ['Freeze-form Extrusion Fabrication', 'extrusion-on-demand', 'ceramic FEF'] | Development of Extrusion-on-Demand for Ceramic Freeze-Form Extrusion Fabrication | Conference paper | https://repositories.lib.utexas.edu//bitstreams/06020cfe-6dc9-4429-a5c0-e29ff9e8fe3e/download | University of Texas at Austin | In the Freeze-form Extrusion Fabrication (FEF) process, extrusion-on-demand (EOD)
refers to the ability to control the start and stop of paste extrusion on demand and is vital
to the fabrication of parts with complex geometries. This paper describes the
development of EOD for ceramic FEF through modeling and control of extrusion force,
selection of appropriate process parameters, and a dwell technique for start and stop of
extrusion. A general tracking controller with integral action is used to allow tracking of a
variety of reference forces while accounting for the variability in the paste properties.
Experiments are conducted to model the process and tune the controller. The developed
technique for EOD is demonstrated to fabricate a number of cross sections and three-dimensional parts from alumina paste. | null | null | null | null | null | null |
['Lee, Kwan H.', 'Park, Joung O.'] | 2019-09-23T16:05:45Z | 2019-09-23T16:05:45Z | 2000 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/75950', 'http://dx.doi.org/10.26153/tsw/3049'] | eng | 2000 International Solid Freeform Fabrication Symposium | Open | Lamination | Development of Freeform Master I – a Desktop RP Machine Based on a New Sheet Lamination Process 283 | Conference paper | https://repositories.lib.utexas.edu//bitstreams/5a775dcd-fd9d-4117-8f64-876b14af1ce9/download | null | A novel process was developed for building Rapid Prototyping(RP) parts using a sheet lamination technique. The building process of existing sheet lamination RP machines consist of the following steps : feeding, lamination and cutting. In this process, the laminated part of an object is often scratched by a cutter or damaged by a laser beam due to the cutting operation after the lamination step. In addition, decubing of the unused portion from the laminated block is difficult. In the new process, however, cutting is performed before lamination. The cutting operation takes place while a paper sheet is firmly attached, using electrostatic force on the plate. Then liquid glue is applied only to the calculated region of the given contour for lamination. This
new process aims to manufacture a $2k RP machine, what we call the Freeform Master I and can use A4 size or letter size sheets of paper. A prototyping machine that demonstrates the concept design was built and further research issues are discussed | null | null | null | null | null | null |
['Leu, Ming C.', 'Garcia, Diego A.'] | 2021-10-07T18:33:50Z | 2021-10-07T18:33:50Z | 2013 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88501', 'http://dx.doi.org/10.26153/tsw/15435'] | eng | 2013 International Solid Freeform Fabrication Symposium | Open | ['Freeze-form Extrusion Fabrication', 'sacrificial material', 'three-dimensional ceramic parts', 'methyl cellulose', 'alumina', 'computer-aided design'] | Development of Freeze-Form Extrusion Fabrication with Use of Sacrificial Material | Conference paper | https://repositories.lib.utexas.edu//bitstreams/afd6068b-fa27-4cb5-b31f-ae775763cdb0/download | University of Texas at Austin | The development of Freeze-form Extrusion Fabrication (FEF) process to fabricate three-dimensional (3D) ceramic parts with use of sacrificial material to build support sections during
the fabrication process is presented in this paper. FEF is an environmentally friendly, additive
manufacturing process that builds 3D parts in a freezing environment layer-by-layer by computer
controlled extrusion and deposition of aqueous colloidal pastes based on computer-aided design
(CAD) models. Methyl cellulose was identified as the support material, and alumina was used as
the main material in this study. After characterizing the dynamics of extruding alumina and
methyl cellulose pastes, a general tracking controller was developed and applied to control the
extrusion force in depositing both alumina and methyl cellulose pastes. The controller was able
to reduce the time constant for the closed-loop system by more than 65% when compared to the
open-loop control system. Freeze-drying was used to remove the water content after the part has
been built. The support material was then removed in the binder burnout process. Finally,
sintering was done to densify the ceramic part. The fabrication of a cube-shaped part with a
square hole in each side that requires depositing the sacrificial material during the FEF process
was demonstrated. | null | null | null | null | null | null |
['Brackett, James', 'Yan, Yongzhe', 'Cauthen, Dakota', 'Kishore, Vidya', 'Lindahl, John', 'Smith, Tyler', 'Ning, Haibin', 'Kunc, Vlastamil', 'Duty, Chad'] | 2021-11-30T19:17:21Z | 2021-11-30T19:17:21Z | 2019 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90518', 'http://dx.doi.org/10.26153/tsw/17437'] | eng | 2019 International Solid Freeform Fabrication Symposium | Open | ['functionally graded materials', 'large-scale additive manufacturing', 'big area additive manufacturing', 'gradient'] | Development of Functionally Graded Material Capabilities in Large-scale Extrusion Deposition Additive Manufacturing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/5273f619-c423-4c74-8096-3d44886d87b4/download | University of Texas at Austin | Additive manufacturing’s (AM) layer-by-layer nature is well-suited to the production of
Functionally Graded Materials (FGM) with discrete material boundaries. Extrusion deposition is
especially advantageous since multiple nozzles easily accommodate the inclusion of additional
materials. However, discrete interfaces and sudden composition changes can limit the
functionality of a printed part through inherently weak bonding. Furthermore, same-layer
transitions are not only difficult to execute, but also further amplify structural weaknesses by
creating multiple discrete interfaces. Therefore, successfully implementing a blended, continuous
gradient will greatly advance the applicability of FGM in additive manufacturing. The pellet-fed
nature and integrated screw design of the Big Area Additive Manufacturing system enables
material mixing needed for development of this capability. Using constituent content analysis,
this study evaluates the transition behavior of a neat ABS/CF-ABS material pair and
characterizes the repeatability of the mixing and printing process, which ultimately leads to
control of site-specific material deposition and properties. | null | null | null | null | null | null |
['Copenhaver, Katie', 'Lamm, Meghan', 'Hubbard, Amber'] | 2024-03-27T16:05:31Z | 2024-03-27T16:05:31Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124500', 'https://doi.org/10.26153/tsw/51108'] | en | 2023 International Solid Freeform Fabrication Symposium | Open | ['porosity', 'fiber alignment', 'sustainability', 'feedstock', 'additive manufacturing'] | DEVELOPMENT OF HIGHLY FILLED BIO-BASED COMPOSITES FOR SUSTAINABLE, LOW-COST FEEDSTOCK: PROCESSING EFFECTS ON POROSITY AND FIBER ALIGNMENT | Conference paper | https://repositories.lib.utexas.edu//bitstreams/56b9a10f-a732-4c7b-aa3b-8cabfc478207/download | University of Texas at Austin | A poly(lactic acid) composite with a high loading of bio-based fibers was developed using
a combination of high-aspect ratio (AR) wood pulp and low-AR wood flour along with viscosity
modifiers to maximize mechanical performance, maintain processability, and lower the cost and
embodied energy of the resulting feedstock. An optimized composite formulation containing 40
wt.% of a blend of high- and low-AR natural fibers with a rice bran-based wax processing aid was
scaled up to produce pellet feedstock using twin screw extrusion, and materials were compression
and injection molded to investigate the effect of fiber alignment on material performance. The
feedstock was then printed on the Big Area Additive Manufacturing system at Oak Ridge National
Laboratory. Print parameters including temperature gradients, screw and gantry speeds, layer
times, and nozzle designs were varied to minimize sharkskinning, warpage, and porosity of the
final parts. A strong effect of the nozzle size on the resulting porosity was observed, and consistent
trends between decreasing porosity, increasing fiber alignment, and increasing mechanical
performance were identified after printing with different nozzles, compression molding, and
injection molding. | null | null | null | null | null | null |
['Groh, Barbara', 'Lee, Kwon Sang', 'Cullinan, Michael', 'Chang, Chih-Hao'] | 2024-03-26T20:37:09Z | 2024-03-26T20:37:09Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124400', 'https://doi.org/10.26153/tsw/51008'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['roll-to-roll fabrication', 'R2R', '3D printing', 'additive manufacturing'] | Development of Joint Manufacturing and In-Line Metrology System for the Patterning of 3D Holographic Structures in Roll-to-Roll Processes | Conference paper | https://repositories.lib.utexas.edu//bitstreams/d879c96b-da27-4991-bc42-bfffad69a4bd/download | University of Texas at Austin | Roll-to-roll (R2R) fabrication at the micro and nano scales promises to increase
manufacturing throughput and reduce unit cost while providing avenues for unique product
applications. By exploring the potential of creating 3D structures with a single lithography step
and being able to confirm success in-situ, existing multilayer patterning error can be mitigated,
since 3D features would be created in one step rather than many. This paper demonstrates steps
being taken to combine a R2R 3D nanolithography tool and an atomic force microscopy (AFM)-
based in-line metrology tool into a functional system for patterning precise 3D structures. An
existing manufacturing system will be adapted to pattern complex structures with a flexible PDMS
mask currently being proven on stationary substrates. Modifications to the AFM system will
include a focus on imaging patterns with varying mechanical properties and tailoring the system
to include gathering mechanical information as well as imaging. By mapping surface features, the
AFM tool will identify surface imperfections and predict failure modes occurring within the 3D
structure. | null | null | null | null | null | null |
['Garcia, D.', 'Watanabe, K.I.', 'Marquez, L.', 'Arrieta, E.', 'Wicker, R.', 'Medina, F.'] | 2023-03-30T16:25:52Z | 2023-03-30T16:25:52Z | 2022 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/117704', 'http://dx.doi.org/10.26153/tsw/44583'] | eng | 2022 International Solid Freeform Fabrication Symposium | Open | ['Inconel 625', 'Inconel 718', 'Directed Energy Deposition (DED)', 'Cladding', 'Additive Manufacturing (AM)'] | Development of Laser Cladding Procedure through Experiment and Analysis Using Powder Blown Directed Energy Deposition | Conference paper | https://repositories.lib.utexas.edu//bitstreams/82f9bca8-d080-4040-a8dc-9a7ae732b137/download | null | Directed Energy Deposition (DED) is one of the categories in Additive Manufacturing
(AM) that has increased its popularity due to the technological advancements in recent years
mainly with advancements in laser power, application of multi-materials, and capability to print
greater dimensions. We are experimenting with a particular process in DED, cladding. For our
experiment, we implemented a powdered feedstock (Inconel 718) which was assessed with distinct
types of substrates in an effort to reduce the time spent on trial-and-error development of cladding
parameters. We developed a procedure to determine a good clad interaction after an examination
of the microstructure and interaction of single beads and a hatched area. The results demonstrate
the ideal powers to be applied in the three substrates assessed with correlation to the dilution
percentage where our target ranged from 10 to 30%. | null | null | null | null | null | null |
['Vath, Carson', 'Masum Billah, Kazi MD', 'Manogharan, Guhprasanna'] | 2024-03-26T20:39:12Z | 2024-03-26T20:39:12Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124401', 'https://doi.org/10.26153/tsw/51009'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['hybrid additive manufacturing', 'embedded electronics', 'additive manufacturing'] | Development of Multimaterial Additive Manufacturing Systems for Embedded Electronics | Conference paper | https://repositories.lib.utexas.edu//bitstreams/8779640e-dbb0-4720-b6fa-01563295df9c/download | University of Texas at Austin | Hybrid additive manufacturing (AM) to integrate discrete material systems and structures in a
monolithic part is a growing research interest. The layer-by-layer deposition system of the AM
build process allows users to integrate multiple materials using custom made tools added to the
gantry systems. State of the art machine development efforts are highly focused on thermoplastic
based material extrusion systems. Compared to the significantly matured thermoplastic material
extrusion AM system, thermoset systems are not well positioned in the market due to the lack of
integrated tooling. This research develops a wire deposition tool that is designed to embed wire
in a photocurable thermoset. Thermoset is relatively stable and does not require heat for
implanting wire. The proposed design method has a more rapid production rate as the extrusion
process can be conducted without any interruptions. The final design was manufactured in PLA
with a traditional FDM machine allowing multiple design iterations to be made quickly. The
final design will be printed on an SLA machine for more accurate, robust parts. | null | null | null | null | null | null |
['Kim, Hyo Chan', 'Saotome, Tsuyoshi', 'Hahn, H. Thomas', 'Bang, Young Gil', 'Bae, Sung Woo'] | 2020-03-10T14:07:03Z | 2020-03-10T14:07:03Z | 8/27/07 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/80205', 'http://dx.doi.org/10.26153/tsw/7224'] | eng | 2007 International Solid Freeform Fabrication Symposium | Open | rapid prototyping | Development of Nanocomposite Powders for the SLS Process to Enhance Mechanical Properties | Conference paper | https://repositories.lib.utexas.edu//bitstreams/fe3810cf-f00a-4576-880b-548a3a2ce879/download | null | In an effort to fabricate prototypes with improved mechanical properties in the dual laser
sintering process, functionalized graphite nanoplatelets were added to the PA-12 powder to
produce a nanocomposite powder. The PA-12 powder was chosen as the matrix polymer
because it has features conducive to laser sintering such as relatively low melting temperature
and high mechanical properties. The GNPs were oxidized through a nitric acid treatment to
improve the interfacial bonding. The resulting nanocomposite powder was layered and sintered
by laser without any sign of agglomeration. Although the result is preliminary, it nevertheless
shows the suitability of the nanocomposite powder for the laser sintering process. | null | null | null | null | null | null |
['Manthiram, A.', 'Chi, F.', 'Johnson, F.', 'Birmingham, B.R.', 'Marcus, H.L.'] | 2018-05-03T17:00:51Z | 2018-05-03T17:00:51Z | 1993 | Mechanical Engineering | doi:10.15781/T2RV0DJ0N | http://hdl.handle.net/2152/65039 | eng | 1993 International Solid Freeform Fabrication Symposium | Open | ['Selective Laser Sintering', 'SLS', 'SLRS', 'nanocomposites'] | Development of Nanocomposites for Solid Freeform Fabrication | Conference paper | https://repositories.lib.utexas.edu//bitstreams/8d624522-5147-477a-8c56-0c2562adc332/download | null | Nanocomposites in which the constituents are mixed on a nanorneter scale can
provide important advantages in the Selective Laser Sintering (SLS) and Selective Laser
Reactive Sintering (SLRS) processes. The larger surface area and grain boundaries in the
nanocolnposites compared to that in the conventional microcomposites are expected to
enhance the solid state diffusion during laser irradiation as well as during any other
subsequent processes. Our strategy is to design and develop nanocomposites in which one
nanosize cOlnponent has a lower melting point than the other nanosize component, either of
which can serve as the matrix phase. The nanoscale dispersion of the low melting
component can aid the sintering process during SLS or SLRS. Nanocomposite powders of
AI203-COOx, Ab03-NiO, A1203-CO and A1203-Ni have been synthesized by sol-gel
processing and are evaluated by SLS. | null | null | null | null | null | null |
['Domack, M. S.', 'Baughman, J. M.'] | 2020-02-17T15:06:43Z | 2020-02-17T15:06:43Z | 2004 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/80005', 'http://dx.doi.org/10.26153/tsw/7030'] | eng | 2004 International Solid Freeform Fabrication Symposium | Open | titanium alloy | Development of Nickel-Titanium Graded Composition Components | Conference paper | https://repositories.lib.utexas.edu//bitstreams/1300705e-76f6-4dbc-aeca-ce533aee79e3/download | null | The potential of various manufacturing methods was evaluated for producing nickel-titanium
graded composition material. The selected test case examined attachment brackets that join
nickel-based metallic thermal protection systems to titanium-based launch vehicle structure. The
proposed application would replace nickel-based components with graded composition
components in an effort to alleviate service induced thermal stresses. Demonstration samples
were produced by laser direct metal deposition, flat wire welding, and ultrasonic consolidation.
Microstructure, general bond quality, and chemistry were evaluated for the components. | null | null | null | null | null | null |
['Guo, C.', 'Lin, F.', 'Ge, W.J.', 'Zhang, J.'] | 2021-10-12T22:13:21Z | 2021-10-12T22:13:21Z | 2014 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88752', 'http://dx.doi.org/10.26153/tsw/15686'] | eng | 2014 International Solid Freeform Fabrication Symposium | Open | ['electron beam selective melting', 'dual-material processing', 'additive manufacturing', 'vibration driven powder'] | Development of Novel EBSM System for High-Tech Material Additive Manufacturing Research | Conference paper | https://repositories.lib.utexas.edu//bitstreams/a162b49b-3525-40f4-ac73-d20a85788ff6/download | University of Texas at Austin | Electron beam is more appropriate for metal additive manufacturing (AM) than laser
because of its high energy converting efficiency and high absorption for various materials. It
becomes a preference for AM study of high-tech material with high melting point, high
brittleness or graded material. A novel electron beam selective melting (EBSM) system with
dual-material processing capability has been developed in Tsinghua University to meet the wide
high-tech material AM research requirement. A vibration driven powder supplier was developed
and the supplier had a high compatibility to various powders. A stable supplying rate and a
supplying accuracy less than 7.5% were obtained with the supplier. Two powders can be supplied
individually to obtain a mixture with tailored proportion for each powder layer. The mixture is
homogenous and the actual proportion is close to the desired value. In order to prolong the
spreading comb’s lifetime and avoid tooth breaking, a low deformation powder spreading device
was designed based on dual inclined combs and a one-way scraping mechanism. The system
provides exchangeable building tanks with sizes of 100 ×100 ×100 mm3
and 250 × 250 × 250
mm3, which can save powder when the part is small and the powder is expensive. The novel
EBSM system is capable of building parts with single material and has a potential of
dual-material processing. | null | null | null | null | null | null |
['Caprio, L.', 'Chiari, G.', 'Demir, A.G.', 'Previtali, B.'] | 2021-11-15T22:42:29Z | 2021-11-15T22:42:29Z | 2018 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90300', 'http://dx.doi.org/10.26153/tsw/17221'] | eng | 2018 International Solid Freeform Fabrication Symposium | Open | ['laser powder bed fusion', 'high temperature', 'preheating', 'TiAl'] | Development of Novel High Temperature Laser Powder Bed Fusion System for the Processing of Crack-Susceptible Alloys | Conference paper | https://repositories.lib.utexas.edu//bitstreams/2a984381-9b12-498e-8013-344aefbc59e4/download | University of Texas at Austin | In the industrial panorama, Laser Powder Bed Fusion (LPBF) systems enable for the near net shaping of
metal powders into complex geometries with unique design features. This makes the technology appealing for
many industrial applications, which require high performance materials combined with lightweight design or
conformal cooling channels. However, many of the alloys that would be ideal for the realisation of these
functional components are classified as difficultly weldable due to their cracking sensitivity. Currently, industrial
SLM systems employ baseplate preheating to minimise these effects although this solution is limitedly effective
along the build direction and often does not achieve high enough temperatures for the realisation of crack-free
specimen. In this work, the design and implementation of a novel inductive high temperature LPBF system is
presented. Furthermore, preliminary results regarding depositions of Titanium Aluminide alloy with and without
preheating are reported, showing the potential of the solution developed. | null | null | null | null | null | null |
['Cohen, Julien', 'Bourell, David L.'] | 2021-11-01T22:14:44Z | 2021-11-01T22:14:44Z | 2016 | Mechanical Engineering | null | https://hdl.handle.net/2152/89777 | eng | 2016 International Solid Freeform Fabrication Symposium | Open | ['pin fin arrays', 'pin fin geometries', 'compact heat exchangers', 'heat exchangers', 'additive manufacturing'] | Development of Novel Tapered Pin Fin Geometries for Additive Manufacturing of Compact Heat Exchangers | Conference paper | https://repositories.lib.utexas.edu//bitstreams/fb46853b-d18f-4690-9153-9aa7f1f34587/download | University of Texas at Austin | Pin fin arrays are widely used to enhance forced convection heat transfer across various
industries, finding application in turbine blade trailing edges, electronics cooling, and broadly for
compact heat exchange. Fin shape greatly affects flow separation and turbulence generation, and
optimizing performance relies on this balance between increased heat transfer and increased
pressure loss along the array. Straight circular and elliptical fins are well-characterized in the
literature, and there exist a scant few studies on tapered configurations with conventional cross-sections. Recent works have investigated straight pin fins with more complex shapes. Tapered,
complex fin geometries represent an avenue for overall performance gains, but manufacturing
them is difficult and time-consuming using traditional machining processes. The unique
capabilities of additive manufacturing now allow their economical fabrication in an increasing
number of fully-dense engineering materials. This work compares 21 pin fin arrays of varying
fin cross-section, taper angle, taper profile, and array patterns using experimental and
computational methods. | null | null | null | null | null | null |
['Vlasea, M.L.', 'Lane, B.', 'Lopez, F.', 'Mekhontsev, S.', 'Donmez, A.'] | 2021-10-20T20:34:05Z | 2021-10-20T20:34:05Z | 2015 | Mechanical Engineering | null | https://hdl.handle.net/2152/89356 | eng | 2015 International Solid Freeform Fabrication Symposium | Open | ['laser powder bed fusion', 'additive manufacturing', 'testbed', 'real-time', 'process control'] | Development of Powder Bed Fusion Additive Manufacturing Test Bed for Enhanced Real-Time Process Control | Conference paper | https://repositories.lib.utexas.edu//bitstreams/6ae5a890-4cad-4b7c-9fda-c14360521078/download | University of Texas at Austin | Laser powder bed fusion (PBF) is emerging as the most popular additive manufacturing (AM)
method for producing metallic components based on the flexibility in accommodating a wide
range of materials with resulting mechanical properties similar to bulk machined counterparts, as
well as based on in-class fabrication speed. Although this approach is advantageous, the current
limitations in achieving predictable and repeatable material and structural properties, geometric
and surface roughness characteristics, and the occurrence of deformations due to residual stresses
results in significant variations in part quality and reliability. Therefore, a better understanding
and control of PBF AM processes is needed. The National Institute of Standards and Technology
(NIST) is developing a testbed to assess in-process and process-intermittent metrology methods
and real-time process control algorithms, and to establish foundations for traceable radiance-based temperature measurements that support high-fidelity process modeling efforts. This paper
will discuss functional requirements and design solutions to meet these distinct objectives. | null | null | null | null | null | null |
['Zhang, Xinchang', 'Cui, Wenyuan', 'Hill, Leon', 'Li, Wei', 'Liou, Frank'] | 2021-11-09T15:35:36Z | 2021-11-09T15:35:36Z | 2018 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90097', 'http://dx.doi.org/10.26153/tsw/17018'] | eng | 2018 International Solid Freeform Fabrication Symposium | Open | ['pre-repair machining', 'component repair', 'defects', 'additive manufacturing'] | Development of Pre-Repair Machining Strategies for Laser-Aided Metallic Component Remanufacturing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/d78eb058-df67-458d-8fc6-cc665f871966/download | University of Texas at Austin | Remanufacturing worn metallic components can prolong the service life of parts that need
frequent replacement but are extremely costly to manufacture, such as aircraft titanium
components, casting dies. Additive manufacturing (AM) technology enables the repair of such
valuable components by depositing filler materials at the worn area layer by layer to regenerate
the missing geometry. In general, damaged parts would be inspected and pre-machined prior to
material deposition to remove oil, residue, oxidized layers or defects located in inaccessible
regions. Therefore, the motivation of this paper is to introduce pre-repair machining strategies for
removing contaminated materials from damaged components and materials surrounding
inaccessible defects to ensure that the target damage is repairable. The current research targets at
common failures comprising surface indentations, erosion, corrosion, wear and cracking, and the
machining strategies for each defect were proposed. Each strategy takes the 3D scanned damaged
model as input and the cut-off volume around the defects is defined by using different approaches.
Pre-repair machining toolpath and program were generated based on the defined cut-off volume
and finally, damaged parts were machined using the proposed strategies. | null | null | null | null | null | null |
['Snarr, Scott E.', 'Snarr, Patrick L.', 'Beaman, Joseph Jr'] | 2023-01-20T16:29:38Z | 2023-01-20T16:29:38Z | 2022 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/117262', 'http://dx.doi.org/10.26153/tsw/44143'] | eng | 2022 International Solid Freeform Fabrication Symposium | Open | carbon fiber | Development of Processing Parameters for the Selective Laser Sintering of Carbon Fiber Reinforced Polyphenylene | Conference paper | https://repositories.lib.utexas.edu//bitstreams/0bd0f0a2-9f4c-40b7-a8cc-bb48824acb53/download | null | The ongoing development of processing parameters for advanced thermoplastic materials
to be fabricated via selective laser sintering (SLS) is rapidly advancing the potential industrial
applications of the manufacturing method. This research focuses on the development of SLS
processing parameters and a tooling application for carbon fiber reinforced Polyphenylene
Sulfide (CF-PPS), a composite material that is novel to SLS. A high temperature SLS research
machine was used to identify suitable processing parameters for the material along with the
tensile strength and geometrical accuracy associated with those parameters. Utilizing the
previously identified parameters, a repair mold for an electronic cable assembly was fabricated.
Mechanical tests were performed on fabricated CF-PPS parts to evaluate the performance of the
material under the mold’s normal operating conditions. The additively manufactured CF-PPS
mold was deemed viable for production and was shipped to our sponsor for further evaluation. | null | null | null | null | null | null |
['Yashiki, Tatsuro', 'Takagi, Tarou'] | 2019-10-23T14:51:51Z | 2019-10-23T14:51:51Z | 2002 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/76752', 'http://dx.doi.org/10.26153/tsw/3841'] | eng | 2002 International Solid Freeform Fabrication Symposium | Open | Reverse Engineering | Development of Reverse Engineering System for Machine Engineering Using 3D Bit-Map Data | Conference paper | https://repositories.lib.utexas.edu//bitstreams/bddcf308-03aa-4ab7-bb19-a7662f0346b1/download | null | In this paper, the authors describe a reverse engineering system, named BitCAT, for machine
engineering using 3D bit-map data obtained from CT digitizers. BitCAT can compose B-Rep CAD
models by fitting parametric primitives, such as flat planes and cylinders, onto 3D bit-map surfaces.
To find boundaries of the primitives effectively, a novel interactive “growing surface method” is
developed and applied in the system. BitCAT is also provided with a method to determine
geometric constraints between the primitives during composition processes. BitCAT can make
very useful CAD models for manipulation and NC machining, because they are properly attached
with geometrical features. A demonstration verifies the faculty and usefulness of the system. | null | null | null | null | null | null |
['Nolan, Thomas', 'Lian, Yongsheng', 'Sussman, Mark'] | 2021-11-03T21:37:14Z | 2021-11-03T21:37:14Z | 2017 | Mechanical Engineering | null | https://hdl.handle.net/2152/89939 | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['simulation tool', 'selective laser melting', 'additive manufacturing'] | Development of Simulation Tools for Selective Laser Melting Additive Manufacturing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/b5d7c07f-422e-48df-82e0-8fad6afb4df1/download | University of Texas at Austin | Two simulations tools have been developed to simulate selective laser melting. One is based on a
multiphase flow solver with dynamic mesh adaptation and massive parallelism. The simulation
tool is based on a first-principles approach to simulate complex additive manufacturing processes
at the entire built part/component level. The developed model takes into account of heating,
melting, powder-to-solid volumetric consolidation, cooling, as well as solidification and shrinkage
that are often ignored in current simulation tools. The second tool is to solve the heat equation only
without considering the flow field and volumetric changes. In both tools laser is modeled as a heat
source. The reported work is our first step toward the development of a complete software suite
that can be executed rapidly on workstations and clusters with accelerators. The simulation tool
can provide AM practitioners and researchers from industry and academic a fast and accurate
simulation-based approach to replace current trial-and-error based practices in industry for process
and material development. | null | null | null | null | null | null |
['Kim, Seongyeon', 'Kim, Kiseong', 'Shin, Jongho'] | 2024-03-26T20:41:02Z | 2024-03-26T20:41:02Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124402', 'https://doi.org/10.26153/tsw/51010'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['deep reinforcement learning', 'soft gripper', 'additive manufacturing'] | Development of Soft Gripper Pneumatic Control System Based on Deep Reinforcement Learning | Conference paper | https://repositories.lib.utexas.edu//bitstreams/32d64e3e-1b79-4351-9b46-fd5140219332/download | University of Texas at Austin | As interest in soft grippers soared, many studies have been performed to control the soft gripper. For the
soft gripper control, a soft gripper model is required first. Usually, the soft gripper modeling has been done
through finite element analysis, which takes lots of time and is effective only in limited situations. Therefore,
research on deep learning-based modeling with a small amount of FEM results has been extensively conducted,
and some satisfactory results have been reported. However, since the model is expressed in the form of a neural
network, it is difficult to utilize general control methods, so research on optimal control or deep reinforcement
learning is being attempted. In this study, we propose a pneumatic control system for the soft gripper control
based on the DRL. To this end, the soft gripper and DRL-based controller are directly developed, and experiments
are performed and the results are analyzed. | null | null | null | null | null | null |
['Brabazon, Dermot', 'Kennedy, Donal', 'Tyrell, Michael'] | 2021-10-01T00:06:54Z | 2021-10-01T00:06:54Z | 9/23/10 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88303', 'http://dx.doi.org/10.26153/tsw/15244'] | eng | 2010 International Solid Freeform Fabrication Symposium | Open | ['rapid prototyping', 'direct shell production', 'three dimensional printing', 'mould'] | Development of Technique for 3D Printed Mould Intricate Rapid Casting | Conference paper | https://repositories.lib.utexas.edu//bitstreams/364a0d1e-db88-4a3f-b969-cf8259834522/download | University of Texas at Austin | The development of rapid prototyping (RP) technologies has proven highly significant in the
efforts to reduce production times for a number of casting processes. Although rapid prototyping
technologies have most commonly be used to produce patterns for investment and sand casting
this study demonstrated the use of direct shell production casting using three dimensional
printing technology. Statistical methods as well as thermal, visual and dimensional analysis were
also applied in order to optimise this rapid casting (RC) process for thin wall non-ferrous parts.
Mould dimensions within ± 0.22 mm were achieved with the developed technique. Higher melt
temperatures and pouring pressures produced castings with better dimensional accuracy. Mould
temperature was not found to affect the casting dimensional accuracy significantly. The results
allow for better dimensional specification of CAD file geometry for the rapid casting process. | null | null | null | null | null | null |
['Mohammed, Mazher Iqbal', 'Ridgway, Mark Gerard', 'Gibson, Ian'] | 2021-11-08T21:05:34Z | 2021-11-08T21:05:34Z | 2017 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90040', 'http://dx.doi.org/10.26153/tsw/16961'] | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['3D printing', 'resection guide', 'radius', '3D modelling', 'implant'] | Development of Virtual Surgical Planning Models and a Patient Specific Surgical Resection Guide for Treatment of a Distal Radius Osteosarcoma using Medical 3D Modelling and Additive Manufacturing Process | Conference paper | https://repositories.lib.utexas.edu//bitstreams/e522a59c-0767-4b93-bc53-a0ebcf23fa35/download | University of Texas at Austin | In this study we will assess the design and fabrication of a patient-specific resection guide to
augment surgical procedures, such as bone grafts and implant placement. Medical imaging data was
used to form a 3-dimensional, digital template model of the target anatomy to incorporate surface
topography information into the guide. The surgical guide was then designed to incorporate slots for
bone cutting, holes for drilling of fixation points, and an optimised geometry which ensure ease of
placement and use. The final device was then manufactured using additive manufacturing, to
accurately replicate the complex surface topography and design features. To validate the design, the
target patient anatomy was replicated using additive manufacturing and a ‘mock’ surgery was
performed to assess the device performance. We found our design allowed for efficient placement
and use during the mock surgery, confirming the potential of the devised process as a robust
methodology for clinical implementation. | null | null | null | null | null | null |
['Fuesing, T.', 'Brown, L.', 'Das, S.', 'Harlan, N.', 'Lee, G.', 'Beaman, J.J.', 'Bourell, D.L.', 'Barlow, J.W.', 'Sargent, K.'] | 2018-11-08T19:51:27Z | 2018-11-08T19:51:27Z | 1996 | Mechanical Engineering | doi:10.15781/T2GQ6RN2H | http://hdl.handle.net/2152/69917 | eng | 1996 International Solid Freeform Fabrication Symposium | Open | ['SLS', 'postprocessing', 'Microstructures'] | Development ofDirect SLS Processing for Production ofCermet Composite Turbine Sealing Components - Part I | Conference paper | https://repositories.lib.utexas.edu//bitstreams/04924b29-4bef-4d58-9875-9de2cf08e33a/download | null | This paper presents the development to date of SLS (selective laser sintering)
technologies for production of cermet composite turbine sealing components, the particular
application being an abrasive blade tip. The component chosen for the application is an integral
part of the low pressure turbine in a IHP'TET (Integrated High Performance Turbine Engine
Technology) demonstrator engine. Both indirect and direct SLS techniques are being developed.
Initial trials and process development involved the use of fugitive polymeric binders. Sequential
refinements were performed to develop a binderless direct SLS process. Results from mechanical
testing indicate that acceptable microstructure and properties are attainable by SLS with
substantial cost savings as compared to the currently employed production method. This is the
rust instance ofdirect SFF methods applied to a functional component | null | null | null | null | null | null |
['Kyogoku, H.', 'Chiba, A.', 'Hashitani, M.', 'Kimijima, T.'] | 2021-11-18T18:53:37Z | 2021-11-18T18:53:37Z | 2019 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90466', 'http://dx.doi.org/10.26153/tsw/17387'] | eng | 2019 International Solid Freeform Fabrication Symposium | Open | ['development status', 'TRAFAM', 'Japan', 'additive manufacturing'] | The Development Status of the National Project by Technology Research Assortiation for Future Additive Manufacturing (TRAFAM) in Japan | Conference paper | https://repositories.lib.utexas.edu//bitstreams/68b7911a-5d62-44e0-8b0b-7bfb5a733330/download | University of Texas at Austin | The Ministry of Economy, Trade and Industry (METI) of Japan established Technology Research
Association for Future Additive Manufacturing (TRAFAM) in order to develop AM technology in
FY2014. The association’s mission is twofold; to develop metal Additive Manufacturing technology and
to develop binder jetting-type machine for the rapid production of sand molds. The goal of TRAFAM
project is the development of innovative metal AM systems that will meet the world’s highest standards and
the development of AM technology for high value-added products for aerospace, medical, and transportation
industries etc. In this paper, the latest development status of the project, especially the development status of
the electron beam PBF type machines, the laser PBF type machine and the laser DED type machines, is
introduced. In addition, the numerical simulation software for metal AM based on multi-scale and multi-physics model is introduced. | null | null | null | null | null | null |
['Klippstein, Helge', 'Duchting, Anne', 'Reiher, Thomas', 'Hengsbach, Florian', 'Menge, Dennis', 'Schmid, Hans-Joachim'] | 2021-11-30T20:01:23Z | 2021-11-30T20:01:23Z | 2019 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90529', 'http://dx.doi.org/10.26153/tsw/17448'] | eng | 2019 International Solid Freeform Fabrication Symposium | Open | ['topology optimization', 'aircraft bracket', 'development', 'production', 'post-processing'] | Development, Production and Post-Processing of a Topology Optimized Aircraft Bracket | Conference paper | https://repositories.lib.utexas.edu//bitstreams/226c5ee3-5824-4b5c-975b-df87ad424180/download | University of Texas at Austin | Structural parts for aviation have very high demands on the development and production
process. Therefore, the entire process must be considered in order to produce high-quality AM
metal parts. In this case study, a conventional part was selected to be optimized for AM. The
process presented includes component selection, design improvement with a novel approach for
topology optimization based on the AMendate algorithm as basis of MSC Apex Generative Design,
component production on a SLM 250 HL and post-processing including heat treatment and surface
smoothing. With the topology optimization a weight reduction of ~60 % could be realized, whereby
the stress distribution is more homogeneous. Furthermore, the challenges of support optimization
and post-processing have to be addressed, in order to produce competitive parts. | null | null | null | null | null | null |
['Skszek, Tim', 'Lowney, M.T.J.'] | 2019-09-23T15:42:41Z | 2019-09-23T15:42:41Z | 2000 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/75941', 'http://dx.doi.org/10.26153/tsw/3040'] | eng | 2000 International Solid Freeform Fabrication Symposium | Open | Reconfiguration | Die Reconfiguration and Restoration Using Laser-Based Deposition 219 | Conference paper | https://repositories.lib.utexas.edu//bitstreams/86895360-b89a-4b00-8dc2-cc2cd8e04a27/download | null | POM Company, Inc., located in Plymouth, Mich., has successfully commercialized the laser-based, free form fabrication process known as DMD,™ or Direct Metal Deposition. Since the company incorporated in 1998, POM has been directed towards the commercialization of the DMD process equipment, and the demonstration of value-added, cost-effective applications specific to the fabrication, repair and reconfiguration of plastic injection molds and die cast tooling. POM currently operates as a service bureau and original equipment manufacturer (OEM), providing engineering analysis, design and fabrication services, as well as the sale of DMD process equipment. An overview of the POM closed-loop, laser-based DMD process, available services and several case study applications are presented. | null | null | null | null | null | null |
['Rudraraju, Anirudh', 'Das, Suman'] | 2021-09-28T20:01:18Z | 2021-09-28T20:01:18Z | 2009-09 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88168', 'http://dx.doi.org/10.26153/tsw/15109'] | eng | 2009 International Solid Freeform Fabrication Symposium | Open | ['Large Area Maskless Photopolymerization', 'bitmaps', 'data compression', 'digital data processing', 'CAD models', 'STL files'] | Digital Data Processing Strategies for Large Area Maskless Photopolymerization | Conference paper | https://repositories.lib.utexas.edu//bitstreams/257508e4-933f-43c4-907d-5386095dfdc7/download | University of Texas at Austin | Large Area Maskless Photopolymerization (LAMP) utilizes scanning spatial light
modulators that require layer slice data in the form of high‐resolution bitmaps. Three different
strategies have been implemented to fill this need. First, bitmaps were generated by direct slicing
of CAD models using Spatial Technology’s ACIS kernel. Second, bitmaps were generated from
STL files through ray‐tracing. Finally, an approach involving reconstruction of topological
information from STL files for efficient slicing and image generation is being developed. This
paper gives a brief description and implementation details of each of these strategies as well as
data compression techniques being pursued by the authors. This work is sponsored by DARPA
grant HR0011‐08‐1‐0075. | null | null | null | null | null | null |
['Aznarte, E.', 'Ayranci, C.', 'Qureshi, A.J.'] | 2021-11-02T17:53:56Z | 2021-11-02T17:53:56Z | 2017 | Mechanical Engineering | null | https://hdl.handle.net/2152/89838 | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['3D printing', 'additive manufacturing', 'mechanical characterization', 'digital light processing', 'DLP', 'vat-photopolymerization', 'stereolithography'] | Digital Light Processing (DLP): Anisotropic Tensile Considerations | Conference paper | https://repositories.lib.utexas.edu//bitstreams/f974ff89-8fad-4361-8ed1-610e2c22f4d3/download | University of Texas at Austin | Digital light processing (DLP) 3D printing is an additive manufacturing (AM) process
used to produce layered parts via photopolymerization. Anisotropy is a common characteristic of
parts produced by DLP. Furthermore, printing conditions affect widely the resulting mechanical
properties. This paper shows the effect of three printing factors on the final mechanical
properties of specimens manufactured using DLP 3D printing. A series of ISO compliant tensile
test specimens were designed, printed and tested. The properties analyzed were the elastic
modulus, ultimate tensile strength, ultimate strain and printing time. Preliminary findings on
design guidelines for Vat Photopolymerization processes are presented in addition to the
economic effect of the studied parameters in terms of the total printing time. | null | null | null | null | null | null |
['Lipkowitz, Gabriel', 'Samuelsen, Tim', 'Hsiao, Kaiwen', 'Dulay, Maria T.', 'Coates, Ian', 'Pan, William', 'Shaqfeh, Eric S.G.', 'DeSimone, Joseph M.'] | 2023-02-17T14:40:08Z | 2023-02-17T14:40:08Z | 2022 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/117484', 'http://dx.doi.org/10.26153/tsw/44365'] | eng | 2022 International Solid Freeform Fabrication Symposium | Open | ['injection continuous liquid interface production (iCLIP)', 'continuous liquid interface production (CLIP)', 'generative design', 'parametric design', 'algorithmic design', 'additive manufacturing', 'microfluidics'] | Digital Microfluidic Design for Injection Continuous Liquid Interface Production of 3D Objects | Conference paper | https://repositories.lib.utexas.edu//bitstreams/0abe7c17-9739-486b-99bc-e01170caf46a/download | null | In additive manufacturing, it is imperative to increase print speeds, use higher
viscosity resins, and print with multiple different resins simultaneously. To this end, we
introduce a new UV-based photopolymerization 3D printing process exploiting a
continuous liquid interface—the deadzone—mechanically fed with resin at elevated
pressures through microfluidic channels dynamically created and integral to the
growing part. Through such mass transport control, injection continuous liquid
interface production, or iCLIP, accelerates printing speeds 5 to 10-fold over current
methods such as continuous liquid interface production (CLIP), can utilize resins an
order of magnitude more viscous than can CLIP, and can readily pattern a single
heterogeneous object with different resins in all Cartesian coordinates. We
characterize the process parameters governing iCLIP and demonstrate use-cases for
rapidly printing carbon nanotube-filled composites, multi-material features with length
scales spanning several orders of magnitude, and lattices with tuneable moduli and
energy absorption. | null | null | null | null | null | null |
['Hadipoespito, George W.', 'Yang, Yong', 'Choi, Hongseok', 'Ning, Guoqing', 'Li, Xiaochun'] | 2019-11-08T15:27:10Z | 2019-11-08T15:27:10Z | 2003 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/78322', 'http://dx.doi.org/10.26153/tsw/5409'] | eng | 2002 International Solid Freeform Fabrication Symposium | Open | Digital Micromirror | Digital Micromirror Device Based Microstereolithography for Micro Structures of Transparent Photopolymer and Nanocomposites | Conference paper | https://repositories.lib.utexas.edu//bitstreams/450da3a8-9142-44a6-9067-0d5b4dfda444/download | null | This paper describes a Digital Micromirror Device (DMD) based ultraviolet (UV)
microstereolithography (µ-SL) system developed for rapid prototyping and manufacturing of
micro 3D structures. Characterization experiments show that the developed the DMD-based
imaging system irradiates an entire photopolymer layer at once, providing reasonable curing
speed and good resolution at a low cost. 2D and 3D micro parts were fabricated. High frequency
ultrasonic vibration (above 20 kHz) was experimented and verified that it can be used to
significantly decrease the leveling time of viscous photopolymer. Furthermore, micro parts were
also fabricated in nanocomposites, which were obtained by ultrasonic mixing of the transparent
photopolymer and nano-sized ceramic particles. High quality micro models fabricated by this
novel process could be used for micro scale investment casting, tooling, devices, and medical
applications. | null | null | null | null | null | null |
['Borstell, D.', 'Friedhofen, B.', 'Kunz, D.'] | 2024-03-27T03:48:35Z | 2024-03-27T03:48:35Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124475', 'https://doi.org/10.26153/tsw/51083'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['3D printing', 'digital modeling', 'cast iron', 'additive manufacturing', 'Cast Iron museum'] | DIGITAL MODEL GENERATION STRATEGY FOR PRINTING MINIATURIZED REPLICA OF HISTORICAL CAST IRON OBJECTS – A USE CASE STUDY | Conference paper | https://repositories.lib.utexas.edu//bitstreams/3be34b22-aa98-47c8-9afe-a987a8947f63/download | University of Texas at Austin | The Cast Iron Museum at Sayn (Germany) hosts a wide range of historic cast iron
objects ranging from highly detailed fly-size figures to oversize eagles and church bells.
Replicating the historical cast iron, i.e. free formed objects, as miniaturized 3D prints for a new
exhibition requires scanning to create the digital model.
High quality of the digital model is a fundamental prerequisite for the production of the
miniaturized 3D print. The influence of software selection and settings during data preparation
from point cloud, mesh and finally solid is highlighted. Printing process selection is the final
step in achieving the required print quality.
A scanning and model generation strategy is developed and described using several
exemplary objects from the Sayn Museum. The final print quality resulting from the selected
scanning process is evaluated. | null | null | null | null | null | null |
['Hinter, J.', 'Basu, D.', 'Flynn, D.F.', 'Harris, R.A.', 'Kay, R.W.'] | 2021-11-09T16:27:58Z | 2021-11-09T16:27:58Z | 2018 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90105', 'http://dx.doi.org/10.26153/tsw/17026'] | eng | 2018 International Solid Freeform Fabrication Symposium | Open | ['hybrid manufacturing', 'digitally-driven', 'ceramics', 'production', 'engineering'] | A Digitally-Driven Hybrid Manufacturing Process for the Flexible Production of Engineering Ceramic Components | Conference paper | https://repositories.lib.utexas.edu//bitstreams/9d4272c8-40ec-47f1-87dc-2ef08e9e2a12/download | University of Texas at Austin | Ceramic materials are a versatile class of materials with numerous applications across a
range of industrial sectors. Predominant methods of manufacturing ceramic components use
template-driven methods, which hampers responsiveness and impose significant design
constraints. This has driven significant interest towards digitally-driven manufacturing
approaches, primarily, additive manufacturing. Additive manufacturing has demonstrated the
rapid production of bespoke and highly complex geometries and designs direct from digital
data without the need for component specific tooling. Yet, when used in isolation these
techniques are restricted by uncontrollable porosity, high shrinkages during firing plus a lack
of process-compatible materials. This paper presents the research and development of a new
hybrid manufacturing process chain for the agile production of engineering grade ceramics
components. The combination of high viscosity ceramic paste extrusion, sacrificial support
deposition and subtractive micro-machining has yielded complex monolithic ceramic
components with feature sizes of 100µm, part densities of ~99.7%, surface roughness down to
~1µm Ra and 3-point bend strength of 218MPa. Since a wide range of materials can be
formulated into visco-elastic pastes they can be readily deposited using this approach. | null | null | null | null | null | null |
['Smith, Matthew A.A.', 'Fry, Nicholas R.', 'Kay, Robert W.', 'Harris, Russell A.'] | 2021-11-09T15:56:27Z | 2021-11-09T15:56:27Z | 2018 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90103', 'http://dx.doi.org/10.26153/tsw/17024'] | eng | 2018 International Solid Freeform Fabrication Symposium | Open | ['microsurface patterning', 'digitally-driven', 'in-process machine vision', 'topographical compensation', 'alignment capability', 'deposition', 'hybrid manufacturing'] | Digitally-Driven Micro Surface Patterning by Hybrid Manufacturing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/63945dc4-19a5-4689-830a-1be8d89a5a96/download | University of Texas at Austin | Aerosol Jet printing is a versatile direct-write method allowing selective deposition and
alteration of surface chemistry on a variety of substrates, making it suitable for incorporation
in a range of hybrid manufacturing processes. The digitally controlled nature of the presented
hybrid manufacturing process enables rapid turnaround of designs, and improvements in
flexibility and complexity compared to established methods. The apparatus and instrumentation
that has been created at the University of Leeds enables specific processing conditions that
result in deposition of features with critical dimensions smaller than 20µm. In this study the
analysis of the effect of process variables on deposition geometries is presented. The features
were assessed by a combination of optical microscopy and white light interferometry. Using in-process machine vision, topographical compensation, and alignment capability the deposition
of material into micropatterned features in poly(dimethylsiloxane) (PDMS) was demonstrated.
High-value applications of this technology for surface functionalisation include electronics and
bio-engineering. | null | null | null | null | null | null |
['Kniepkamp, Michael', 'Fischer, Jakob', 'Abele, Eberhard'] | 2021-10-28T20:26:08Z | 2021-10-28T20:26:08Z | 2016 | Mechanical Engineering | null | https://hdl.handle.net/2152/89691 | eng | 2016 International Solid Freeform Fabrication Symposium | Open | ['dimensional accuracy', 'sub-millimeter parts', '316L', 'steel powders', 'micro selective laser melting'] | Dimensional Accuracy of Small Parts Manufactured by Micro Selective Laser Melting | Conference paper | https://repositories.lib.utexas.edu//bitstreams/7177d2d1-da73-4a11-ad6a-d545e9da4ba1/download | University of Texas at Austin | While selective laser melting of metallic parts is already widely used in today’s industry, problems in this
process still occur when using small parts with dimensions of less than 5 mm. Micro selective laser melting can
fill gaps with layer sizes of less than 10 microns and powders with particle sizes smaller than 5 microns. In this
paper the dimensional accuracy of parts with sub millimeter features using 316L steel powder is investigated.
Test specimens with different features like slopes, overhangs and sharp radii were built applying different scan
strategies. The parts were 3D scanned and compared to the CAD data to analyze their accuracy. Based on the
results, optimized scan strategies for the different features were developed to increase the parts’ overall
dimensional accuracy. | null | null | null | null | null | null |
['Mitchell, W.F.', 'Lang, D.C.', 'Merdes, T.A.', 'Reutzel, E.W.', 'Welsh, G.S.'] | 2021-11-01T20:59:22Z | 2021-11-01T20:59:22Z | 2016 | Mechanical Engineering | null | https://hdl.handle.net/2152/89748 | eng | 2016 International Solid Freeform Fabrication Symposium | Open | ['dimensional accuracy', 'Ti-6Al-4V', 'direct metal laser sintering', 'production quality'] | Dimensional Accuracy of Titanium Direct Metal Laser Sintered Parts | Conference paper | https://repositories.lib.utexas.edu//bitstreams/13156315-df48-4564-a809-954795f23340/download | University of Texas at Austin | To address concerns regarding quality of production parts created using the Additive
Manufacturing (AM) process, a study was conducted to quantify the dimensional accuracy of said
parts. Fourteen AM builds were manufactured in Ti-6Al-4V material across two EOS DMLS
machines (EOSINT M 280 and EOS M 290). In addition to studying the impact of machine-to-machine variability, other factors potentially impacting final dimensional accuracy were studied,
including: powder state (virgin or reused); post-processing steps (heat treatment and part removal
from substrate); location of part on substrate; and nominal part size. The results of the dimensional
analysis showed that the individual machine itself was the dominant factor impacting dimensional
accuracy. Also, a non-linear relationship between dimensional accuracy and nominal part size was
identified, which would require a more complex machine calibration technique to correct. | null | null | null | null | null | null |
['Terry, Shane', 'Fidan, Ismail', 'Tantawi, Khalid'] | 2021-11-18T00:27:19Z | 2021-11-18T00:27:19Z | 2019 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90370', 'http://dx.doi.org/10.26153/tsw/17291'] | eng | 2019 International Solid Freeform Fabrication Symposium | Open | ['fused filament fabrication', 'metal powder filament', 'polylactic acid', 'metal 3D printing'] | Dimensional Analysis of Metal Powder Infused Filament - Low Cost Metal 3D Printing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/0e11710f-5c28-4b2b-9e53-c94b18047aab/download | University of Texas at Austin | The process of Additive Manufacturing (AM) is the newest form of fabrication with the
primary method being layer-by-layer production. The most common form of this technology is
Fused Filament Fabrication (FFF), where material is deposited layer by layer to produce a highly
customized part. When compared to subtractive manufacturing the production of waste is greatly
reduced. This study presents some innovations on a new metal fabrication technique for FFF
printing. By printing a PolyLactic Acid (PLA) compliant metal powder composite filament, a part
can be made with approximately 90% metal composition and sintered. The sintering process
removes the PLA bonding leaving a 100% metal part fabricated on a low cost FFF printer. Overall,
this study reports the initial findings on dimensional changes in low cost metal 3D Printing process. | null | null | null | null | null | null |
['Murray, R.A.', 'Foy, G.', 'Clemon, L.'] | 2021-11-18T17:37:19Z | 2021-11-18T17:37:19Z | 2019 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90441', 'http://dx.doi.org/10.26153/tsw/17362'] | eng | 2019 International Solid Freeform Fabrication Symposium | Open | ['cold spray', 'scanning', 'part inspection', 'metal additive', 'high-velocity particle spray'] | Dimensional Comparison of a Cold Spray Additive Manufacturing Simulation Tool | Conference paper | https://repositories.lib.utexas.edu//bitstreams/c2f2b0bd-2b97-48ea-9f33-73b6e3f0e1e6/download | University of Texas at Austin | High-velocity particle spray greatly increases metal additive manufacturing deposition speed over
other commercial methods. Accurate prediction and measurement of this process will improve process
control. A LightSPEE3D machine fabricated symmetric copper components. On-board software
predicts the build geometry (.stl) given the input geometry and the build settings. Assessment of
prediction accuracy is needed to enable rapid part design and print setting optimization. White-light
3D-scanning and high-fidelity optical microscopy scans are compared to the simulation and intended
20mm cubes using hausdorf distance:
1. Control-repeated scans: 0.38±0.48mm, max:2.25mm
2. Intended-original vs. scans: 1.42±1.58mm, max:6.72mm
3. Software-predicted vs. scans: 0.44±0.66mm, max:3.97mm
Discrepancies up to 6.72mm and asymmetric fabrication artifacts were identified. The reduction in the
hausdorf distance for simulation vs intended-original, and larger distance of the simulation compared
to control, indicate the simulation tool may enable rapid optimization given over/under spray
quantification. Recommendations for reducing asymmetric fabrication artifacts and over/underspray
are provided. | null | null | null | null | null | null |
['Winmill, David L.', 'Hoopes, Daniel M.', 'Jayanthi, Suresh S.'] | 2019-02-22T17:32:32Z | 2019-02-22T17:32:32Z | 1998 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/73463', 'http://dx.doi.org/10.26153/tsw/613'] | eng | 1998 International Solid Freeform Fabrication Symposium | Open | ['Rapid prototyping technologies', 'stereolithography'] | Dimensional Issues in Stereolithography | Conference paper | https://repositories.lib.utexas.edu//bitstreams/4d64ba71-9666-4471-85c6-b1ec0a6efa38/download | null | New stereolithography photopolymers have recently been introduced that provide a wider
range of functional properties similar to those of high-density polyethylene. One of the
important criteria for these materials is the dimensional accuracy and stability in end-use
applications as mold masters or the actual functional parts. This work investigates the
dimensional stability of one of these new materials with varying amounts of exposure during
build. The effect of aging on the part dimensions is reported. The result of environmental
humidity extremes at ambient temperature on part dimensions is investigated and compared for
parts made from two different families of stereolithography resins, namely DuPont Somos® 7100
and Somos® 8100. | null | null | null | null | null | null |
['Wang, Wanlong', 'Conley, James G', 'W Stoll, Henry'] | 2019-02-25T17:42:28Z | 2019-02-25T17:42:28Z | 1998 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/73476', 'http://dx.doi.org/10.26153/tsw/626'] | eng | 1998 International Solid Freeform Fabrication Symposium | Open | ['SFF', 'CAD'] | Dimensional Variability Analysis ln Post-Processing Of Rapid Tooling | Conference paper | https://repositories.lib.utexas.edu//bitstreams/133ba5a1-0725-4965-92ae-acc4a3263c0c/download | null | Rapid tooling for sand casting can be made by creating pattern with elements made by solid
freeform fabrication (SFF) devices. Using this approach, post-processing and hand finishing
remain as necessary steps to improve the surface finish quality of the pattern. For rapid·.tooling
using laminated object manufacturing (LOM) models, post-processing includes decubing,
sanding and sealing followed by integration with a match plate and/or conventional cope & drag
pattern elements. Since the critical finishing operations are intensively manual, it is difficult to
estimate the dimensional capability of rapid tooling by.LaM process. The Objective of this paper
is to use statistics to evaluate dimensional variability associated with postprocessing using the
accepted industry best practice. | null | null | null | null | null | null |
['Ruan, Jianzhong', 'Tang, Lie', 'Sparks, Todd E.', 'Landers, Robert G.', 'Liou, Frank'] | 2020-03-11T15:43:16Z | 2020-03-11T15:43:16Z | 9/10/08 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/80257', 'http://dx.doi.org/10.26153/tsw/7276'] | eng | 2008 International Solid Freeform Fabrication Symposium | Open | Solid Freeform Fabrication | Direct 3D Layer Metal Deposition | Conference paper | https://repositories.lib.utexas.edu//bitstreams/8a3c7b63-8cc0-46e6-a3a0-91ee19b5a656/download | null | null | null | null | null | null | null | null |
['Frank, Matthew C.', 'Harrysson, Ola', 'Wysk, Richard A.', 'Chen, Niechen', 'Srinivasan, Harshad', 'Hou, Guangyu', 'Keough, Carter'] | 2021-11-04T15:51:00Z | 2021-11-04T15:51:00Z | 2017 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/89989', 'http://dx.doi.org/10.26153/tsw/16910'] | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['direct additive substrate hybrid manufactured', 'DASH', 'geometric specification', 'geometric accuracy', 'out of envelope'] | Direct Additive Subtractive Hybrid Manufacturing (DASH) – An Out of Envelope Method | Conference paper | https://repositories.lib.utexas.edu//bitstreams/03287dc0-dcb9-46fe-a9e5-73a4c2cd8915/download | University of Texas at Austin | This work addresses a critical issue affecting the adoption of metal additive manufacturing (AM)
methodologies; creating a system that can produce a mechanical product to final geometric
specification. To date, almost all functional metal AM parts have required secondary processing
that in many cases can more than double the cost of the final part. A Direct Additive and
Subtractive Hybrid (DASH) manufacturing system using both additive and then subtractive
processing has been developed so that mechanical parts can be “digitally manufactured” to meet
the final required geometric accuracy. The approach includes the development of a software
system to link additive and subtractive manufacturing, using extensions to the AMF format, to
maintain product design features along with their tolerance specifications. It also introduces the
idea of sacrificial fixtures that are automatically designed into the parts to allow subsequent
fixturing in the CNC mill. Once in the milling machine, a part localization system identifies the
part and its location, along with capturing the geometry of any remaining AM support material left
on the part. Finally, all CNC code is automatically generated and the finishing process can be
executed in a lights-out operation. This work provides a drastic reduction in post processing time
and cost. It further enables expansion of metal AM and uniquely addresses the challenge of out-of-envelope hybrid manufactured parts. | null | null | null | null | null | null |
Frazier, William E. | 2021-09-30T20:16:32Z | 2021-09-30T20:16:32Z | 9/23/10 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88294', 'http://dx.doi.org/10.26153/tsw/15235'] | eng | 2010 International Solid Freeform Fabrication Symposium | Open | ['Navy Workshop', 'direct digital manufacturing', 'technical challenges', 'research & development', 'R&D', 'R&D roadmap', 'innovative structural design', 'maintenance and repair', 'qualification and certification methodology', 'DDM science & technology'] | Direct Digital Manufacturing of Metallic Components: Vision and Roadmap | Conference paper | https://repositories.lib.utexas.edu//bitstreams/457c2d4d-90d2-410c-88f6-5cc3bb7e23d8/download | University of Texas at Austin | null | null | text | null | null | null | null |
['Chi, Xiaopeng', 'Yang, Hongyi', 'Shoufeng, Yang', 'Evans, Julian R. G.'] | 2020-02-28T20:40:17Z | 2020-02-28T20:40:17Z | 9/14/06 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/80119', 'http://dx.doi.org/10.26153/tsw/7140'] | eng | 2006 International Solid Freeform Fabrication Symposium | Open | scaffolds | Direct Extrusion Freeforming of Ceramic Pastes | Conference paper | https://repositories.lib.utexas.edu//bitstreams/3efc3bb4-fba5-4a42-be9b-fb73429a4f20/download | null | Microextrusion freeforming of ceramic lattices from high solids ceramic pastes provides
multi-scale hierarchical void structures with the advantages of low shrinkage stress and high
sintered density. Alumina lattices were directly fabricated using 80-500 Pm diameter filaments.
We report here on the implementation of design and fabrication of these scaffolds for band gap
materials and micro fluidic devices. | null | null | null | null | null | null |
['Harrysson, Ola L.A.', 'Cormier, Denis R.', 'Marcellin-Little, Denis J.', 'Jajal, K.R.'] | 2019-11-21T18:00:41Z | 2019-11-21T18:00:41Z | 2003 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/78548', 'http://dx.doi.org/10.26153/tsw/5604'] | eng | 2003 International Solid Freeform Fabrication Symposium | Open | Direct Fabrication | Direct Fabrication of Metal Orthopedic Implants Using Electron Beam Melting Technology | Conference paper | https://repositories.lib.utexas.edu//bitstreams/85fb7e27-cb2b-42e4-88f4-dc4db0b09195/download | null | Metal orthopedic implants have been used for many decades with great success.
Replacement joints and plates for bone fractures are usually made from titanium, cobaltchromium or stainless steel. Through recent advancements in biomodeling, custom orthopedic
implants can be designed. However, fabrication of these custom implants can be prohibitively
expensive with traditional processes. With the introduction of Electron Beam Melting (EBM),
direct fabrication of fully dense metal components is possible. In this paper, the development of
titanium for the EBM-process will be discussed, and direct fabrication of custom designed
orthopedic implants made out of steel and titanium will be demonstrated. | null | null | null | null | null | null |
['Klosterman, Donald', 'Chartoff, Richard', 'Agarwala, Mukesh', 'Fiscus, Ira', 'Murphy, John', 'Cullen, Sean', 'Yeazell, Mark'] | 2019-03-17T14:04:40Z | 2019-03-17T14:04:40Z | 1999 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/73699', 'http://dx.doi.org/10.26153/tsw/841'] | eng | 1999 International Solid Freeform Fabrication Symposium | Open | ['LOM', 'PMC'] | Direct Fabrication of Polymer Composite Structures with Curved LOM | Conference paper | https://repositories.lib.utexas.edu//bitstreams/b3965f93-7cdf-46b9-bdda-20dda9fda7d6/download | null | This report describes the application of Curved LOM to the direct fabrication of polymer matrix
composites (PMCs). The overall methodology of directly fabricating PMC parts involved the use of the
Curved LOM machine to lay-up and shape "green" composite laminates from prepreg feedstocks,
followed by vacuum bag / oven cure and consolidation. The conventional Curved LOM laminator was
replaced with a vacuum thermoforming apparatus to better accommodate the bonding of commercially
available prepregs. The study also demonstrated that it is possible to interface a general composite design
sofiware package with the Curved LOM machine via the curved slice file (.CSF) format. Taken together,
these two improvements allow for improved flexibility in manufacturing PMC components, from both a
material handling and a design point-of-view. A simple C-shaped panel was fabricated and tested to
demonstrate the overall feasibility of the process for PMCs. A glass fiber 1 epoxy prepreg obtained from a
commercial supplier was used as a model material system. It was found that the cumulative accuracy of
the overall process was good, and the mechanical properties of the laminates were acceptable for nonstructural applications for which the material is normally used. | null | null | null | null | null | null |
['Maxwell, J. L.', 'Pegna, J.', 'Messia, D.', 'DeAngelis, D.'] | 2018-11-14T16:46:02Z | 2018-11-14T16:46:02Z | 1996 | Mechanical Engineering | doi:10.15781/T28G8G34G | http://hdl.handle.net/2152/70238 | eng | 1996 International Solid Freeform Fabrication Symposium | Open | ['Solid Area Laser Deposition', 'Chemical Vapor Deposition', 'Graphite'] | Direct Feedback Control of Gas-Phase Laser-Induced Deposition | Conference paper | https://repositories.lib.utexas.edu//bitstreams/4cb30558-e50a-466b-98d7-0509a2fae945/download | null | Three-dimensional laser Chemical vapor deposition (3D-LCVD) or SALD, was used to
prototype metallic and ceramic microstructures. Iron, nickel, and steel metal forms were grown
from organic and halogen based precursors. Through the simultaneous use of multiple precursors,
specific nickel-iron based alloys were produced. By observing the emission spectra during
growth, a measure ofthe volumetric growth rate, was obtained. Direct, PID control ofthe process
was then possible using the growth rate measurement as real-time feedback. Calibrated infrared
photographs of evolving microstructures were taken at various wavelengths, giving a measure of
the temperature gradient over the growth zone. While radiation contributes to heat losses at high
temperatures, enhanced convection is the dominant heat transfer mechanism due to the small
dimensions of the heated area. Enhanced growth rates, induced by convective flow, were also
observed. The heat and mass transfer coefficients were determinedfor various processing conditions,
and compare well with experimental data. Axi-symmetric rods may also be grown in both
the kinetic and transport-limited regimes, and a systematic study of the precursor pressure and
deposit temperature during growth yielded distinct growth regimes, influn, ced by the interplay of
heat losses and diffusive transport. | null | null | null | null | null | null |
['Cohen, D. L.', 'Malone, E.', 'Lipson, H.', 'Bonassar, L. J.'] | 2020-02-17T15:27:31Z | 2020-02-17T15:27:31Z | 8/4/04 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/80010', 'http://dx.doi.org/10.26153/tsw/7035'] | eng | 2004 International Solid Freeform Fabrication Symposium | Open | Alginate gels | Direct Freeform Fabrication of Spatially Heterogeneous Living Cell-Impregnated Implants | Conference paper | https://repositories.lib.utexas.edu//bitstreams/f4b96184-0e7e-4a6d-aa06-eefa340e1a53/download | null | The objectives of this work are the development of the processes, materials, and tooling to
directly “3-D print” living, pre-seeded, patient-specific implants of spatially heterogeneous
compositions. The research presented herein attempts to overcome some of the challenges to
scaffolding, such as the difficulty of producing spatially heterogeneous implants that require
varied seeding densities and/or cell-type distributions. In the proposed approach, living implants
are fabricated by the layer-wise deposition of pre-cell-seeded alginate hydrogel. Although
alginate hydrogels have been previously used to mold living implants, the properties of the
alginate formulations used for molding were not suitable for 3-D printing. In addition to changing
the formulation to make the alginate hydrogels “printable,” we developed a robotic hydrogel
deposition system and supporting CAD software to deposit the gel in arbitrary geometries. We
demonstrated this technology’s capabilities by printing alginate gel implants of multiple materials
with various spatial heterogeneities, including, implants with completely embedded material
clusters. The process was determined to be both viable (94±5% n=15) and sterile (less than one
bacterium per 0.9 µL after 8 days of incubation). Additionally, we demonstrated the printing of a
meniscus cartilage-shaped gel generated directly from a CT Scan. The proposed approach may
hold advantages over other tissue printing efforts [5,9]. This technology has the potential to
overcome challenges to scaffolding and could enable the efficient fabrication of spatially
heterogeneous, patient-specific, living implants. | null | null | null | null | null | null |
Guduri, Sashidhar | 2018-05-03T19:51:07Z | 2018-05-03T19:51:07Z | 1993 | Mechanical Engineering | doi:10.15781/T2N010B19 | http://hdl.handle.net/2152/65071 | eng | 1993 International Solid Freeform Fabrication Symposium | Open | ['Department of Mechanical Engineering', 'SFF', 'Three Dimensional Printing', 'computer models'] | Direct Generation of Contour Files from Constructive Solid Geometry Representations | Conference paper | https://repositories.lib.utexas.edu//bitstreams/c0a1b45a-417b-4679-8c27-4bb2bcfeee35/download | null | Geometry processing for layer-based Solid Freeform Fabrication consists of at least two
steps: slicing the geometry to obtain the part contours for each layer, and scan-converting the
layers for laser scanning (or other device-dependent in-layer processing). This paper discusses
the generation of contour files directly from Constructive Solid Geometry (CSG) representations
for the Selective Laser Sintering process. Previous work at The University of Texas focused on
slicing CSG representations composed of quadric primitives. This paper extends previous work
at UT to include the torus, a fourth degree surface, as one of the CSG primitives. Slicing a torus
results in a fourth degree equation in two variables, which represents a curve in two-dimensional
real space. For. some special cases, this fourth degree equation may be sub-divided into two
second degree equations. For the cases where the fourth degree equation cannot be sub-divided,
a method is presented to approximate the fourth degree curve with second degree curve
segments. | null | null | null | null | null | null |