|About this Abstract
||MS&T21: Materials Science & Technology
||Additive Manufacturing: Alloy Design to Develop New Feedstock Materials III
||Solidification Cracking in Binary Al-Cu Alloys (1.5, 3.0, 4.5, 6.0, and 10 wt.% Cu) Additively Manufactured by Laser Powder Bed Fusion
||Keegan Muller, Thinh Huynh, Holden Hyer, Sharon M Park, Le Zhou, Jeongmin Woo, Abhishek Mehta, Brandon A McWilliams, Kyu Cho, Yongho Sohn
|On-Site Speaker (Planned)
Understanding of solidification cracking and its composition dependence are crucial in designing alloys that are suitable for laser powder bed fusion (LPBF). In this study, the crack density of Al-Cu binary alloys (1.5, 3.0, 4.5, 6.0, and 10 wt.% Cu), produced by LPBF from gas atomized powders, were determined by metallography, and examined with respect to Kou’s cracking susceptibility index, |dT/d(fs)1/2|, derived from the Scheil-Gulliver equation. Maximum crack density was experimentally observed for alloys with higher solute content than that predicted by cracking susceptibility model (i.e., no diffusion in solid and equilibrium partition coefficient). Presence of solid-state diffusion and/or variation in partition coefficient on cracking susceptibility index, based on Kurz and Fisher’s modified Scheil-Gulliver equation, were examined to deduce their respective influence on the composition-dependence and magnitude of LPBF solidification cracking index. Partition coefficients appropriate for LPBF solidification were estimated based on diffusion coefficients available in literature for Al-Cu alloys.