Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Engineering
Direct 3d Printing Of Silica Doped Transparent Magnesium Aluminate Spinel Ceramics, John M. Pappas, Xiangyang Dong
Direct 3d Printing Of Silica Doped Transparent Magnesium Aluminate Spinel Ceramics, John M. Pappas, Xiangyang Dong
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Transparent magnesium aluminate spinel ceramics were additively manufactured via a laser direct deposition method in this study. With a minimum porosity of 0.3% achieved, highly transparent spinel samples with the highest total optical transmittance of 82% at a wavelength of 632.8 nm, were obtained by a 3D printing approach. However, cracking was found to be a major issue affecting printed spinel samples. To control prevalent cracking, the effect of silica dopants was investigated. Increased silica dopants reduced average total crack length by up to 79% and average crack density by up to 71%. However, a high dopant level limited optical …
Laser Metal Deposition Of An Alcocrfeniti₀.₅ High-Entropy Alloy Coating On A Ti6al4v Substrate: Microstructure And Oxidation Behavior, Wenyuan Cui, Wei Li, Wei Ting Chen, Frank W. Liou
Laser Metal Deposition Of An Alcocrfeniti₀.₅ High-Entropy Alloy Coating On A Ti6al4v Substrate: Microstructure And Oxidation Behavior, Wenyuan Cui, Wei Li, Wei Ting Chen, Frank W. Liou
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Ti6Al4V has been recognized as an attractive material, due to its combination of low density and favorable mechanical properties. However, its insufficient oxidation resistance has limited the high-temperature application. In this work, an AlCoCrFeNiTi0.5 high-entropy alloy (HEA) coating was fabricated on a Ti6Al4V substrate using laser metal deposition (LMD). The microstructure and isothermal oxidation behaviors were investigated. The microstructure of as-deposited HEA exhibited a Fe, Cr-rich A2 phase and an Al, Ni, Ti-enriched B2 phase. Its hardness was approximately 2.1 times higher than that of the substrate. The oxidation testing at 700⁰C and 800⁰C suggested that the HEA coating …
Effects Of Zirconia Doping On Additively Manufactured Alumina Ceramics By Laser Direct Deposition, John M. Pappas, Aditya R. Thakur, Xiangyang Dong
Effects Of Zirconia Doping On Additively Manufactured Alumina Ceramics By Laser Direct Deposition, John M. Pappas, Aditya R. Thakur, Xiangyang Dong
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The ability to additively manufacture functional alumina ceramics has the potential to lower manufacturing costs and development time for complex components. In this study, the doping effects of zirconia on laser direct deposited alumina ceramics were investigated. The microstructure of the printed samples was analyzed in terms of grain size and composition distribution. The addition of zirconia was found to accumulate along alumina grain boundaries and resulted in significant grain refinement. The zirconia doping largely reduced crack formation during processing compared to that of pure alumina samples. In the case of 10 wt% zirconia, cracking during deposition was nearly completely …
Aluminum Parts Fabricated By Laser-Foil-Printing Additive Manufacturing: Processing, Microstructure, And Mechanical Properties, Chia Hung Hung, Yingqi Li, Austin Sutton, Wei Ting Chen, Xiangtao Gong, Heng Pan, Hai Lung Tsai, Ming-Chuan Leu
Aluminum Parts Fabricated By Laser-Foil-Printing Additive Manufacturing: Processing, Microstructure, And Mechanical Properties, Chia Hung Hung, Yingqi Li, Austin Sutton, Wei Ting Chen, Xiangtao Gong, Heng Pan, Hai Lung Tsai, Ming-Chuan Leu
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Fabrication of dense aluminum (Al-1100) parts (>99.3% of relative density) by our recently developed laser-foil-printing (LFP) additive manufacturing method was investigated as described in this paper. This was achieved by using a laser energy density of 7.0 MW/cm2 to stabilize the melt pool formation and create sufficient penetration depth with 300 μm thickness foil. The highest yield strength (YS) and ultimate tensile strength (UTS) in the LFP-fabricated samples reached 111 ± 8 MPa and 128 ± 3 MPa, respectively, along the laser scanning direction. These samples exhibited greater tensile strength but less ductility compared to annealed Al-1100 samples. Fractographic …