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Full-Text Articles in Engineering
Effect Of The Melt Pool Boundary Network On The Anisotropic Mechanical Properties Of Selective Laser Melted 304l, Myranda Spratt, Joseph William Newkirk, Okanmisope Fashanu, K. Chandrashekhara
Effect Of The Melt Pool Boundary Network On The Anisotropic Mechanical Properties Of Selective Laser Melted 304l, Myranda Spratt, Joseph William Newkirk, Okanmisope Fashanu, K. Chandrashekhara
Materials Science and Engineering Faculty Research & Creative Works
Anisotropic mechanical properties are a well-known issue in selective laser melted parts. The microstructure produced by selective laser melting (SLM) is directional, including the solidified melt pool structures and grains. This work investigates the melt pool boundary's effects on 304L stainless steel's compressive properties. 304L stainless steel solid cylinders were built using a pulse laser SLM machine in four directions using three hatch angle rotations: 0⁰, 67⁰, and 105⁰ . The twelve samples were compression tested, and the results were analyzed. Numerical models were also created with the different hatch angles and directions. The melt pool boundary network (MPBN) in …
Fabricating Tinicu Ternary Shape Memory Alloy By Directed Energy Deposition Via Elemental Metal Powders, Yitao Chen, Xinchang Zhang, Mohammad Masud Parvez, Joseph William Newkirk, Frank W. Liou
Fabricating Tinicu Ternary Shape Memory Alloy By Directed Energy Deposition Via Elemental Metal Powders, Yitao Chen, Xinchang Zhang, Mohammad Masud Parvez, Joseph William Newkirk, Frank W. Liou
Materials Science and Engineering Faculty Research & Creative Works
In this paper, a TiNiCu shape memory alloy single-wall structure was fabricated by the directed energy deposition technique with a mixture of elemental Ti, Ni, and Cu powders following the atomic percentage of Ti50Ni45Cu5 to fully utilize the material flexibility of the additive manufacturing process to develop ternary shape memory alloys. The chemical composition, phase, and material properties at multiple locations along the build direction were studied, using scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, Vickers hardness test-ing, tensile testing, and differential scanning calorimetry. The location-dependent compositions of martensitic TiNi and austenitic TiNi phases, mechanical properties, and functional properties …
Absorption Of Nitrogen During Pulsed Wave L-Pbf Of 17-4 Ph Steel, Ben Brown, Joseph William Newkirk, Frank W. Liou
Absorption Of Nitrogen During Pulsed Wave L-Pbf Of 17-4 Ph Steel, Ben Brown, Joseph William Newkirk, Frank W. Liou
Materials Science and Engineering Faculty Research & Creative Works
In the fabrication of 17-4 PH by laser powder bed fusion (L-PBF) the well-documented occurrence of large amounts of retained austenite can be attributed to an elevated concentration of nitrogen present in the material. While the effects of continuous wave (CW) laser processing on in-situ nitrogen absorption characteristics have been evaluated, power modulated pulsed wave (PW) laser processing effects have not. In this study the effects of PW L-PBF processing of 17-4 PH on nitrogen absorption, phase composition, and mechanical performance are explored using commercially available PW L-PBF equipment and compared to samples produced by CW L-PBF. PW L-PBF samples …