SIMULATION OF ORBITAL FORMING PROCESS
In this study the feasibility of 3D FEM simulation of the orbital forming process was investigated by evaluating the simulation time. Commercial FEA software DEFORM 3D v4.0 that has an efficient computation algorithm for simulating incremental forming process was used for the simulations and the savings in computation time was determined. In order to provide reliable flow stress for the simulation, a finite element based inverse analysis technique has been introduced. Results show that developed inverse analysis technique is efficient and accurate for use in 3D FEM simulation for process optimization.
APPLICATION OF TECHNOLOGY TO COMPETE SUCCESSFULLY IN PRECISION FORGING
Global competition has intensified in the manufacturing world in general, and specifically in the forging industry. Forging firms from Asian countries, especially China and India, have established a significant presence in the global market by improving their technology and innovation, and delivering cost-effective solutions. They also have the added advantage of an inexpensive and highly motivated labor force. Some of these countries also receive support from their government in the form of tax breaks, free training, and an artificially maintained favorable foreign exchange rate. Thus, the forging industry of industrialized high labor rate countries can only survive in this global market by reducing labor costs (which often requires extensive capital investment for automation), increasing material utilization by reducing flash and scrap losses, by reducing lead times and above all by maintaining a technological advantage over their competition.
A bifunctional Cr/Yb/Tm:Ca3Ga2Ge3O12 phosphor with near-infrared long-lasting phosphorescence and upconversion luminescence.
Currently, upconversion nanocrystals and long-lasting phosphorescent particles have attracted extensive research interest for their possible applications as bioimaging probes. However, there are few reports concerning the achievement of both upconversion luminescence of lanthanide ions and long-lasting phosphorescence of transition metal ions in a sole host so far. Herein, we demonstrate a novel calcium gallium germanium garnet (Ca3Ga2Ge3O12) host where lanthanide ions such as Tm(3+)/Yb(3+) and transition metal ions such as Cr(3+) can be easily incorporated through substituting the Ca(2+) and Ga(3+) respectively. This Cr/Yb/Tm:Ca3Ga2Ge3O12 phosphor exhibits both broadband near-infrared long-lasting phosphorescence of Cr(3+) with an afterglow time of more than 7000 s and near-infrared to near-infrared upconversion luminescence of Tm(3+). Impressively, it is evidenced that the addition of Yb(3+)/Tm(3+) into Cr:Ca3Ga2Ge3O12 not only results in Tm(3+) upconversion luminescence but also greatly increases Cr(3+) afterglow time. Based on excitation/emission, three-dimensional thermoluminescence, and time-resolved luminescence spectra, the related long-lasting phosphorescence and upconversion luminescent mechanisms are systematically discussed as well.