(V) INVITED: Understanding and Improving the Buildability of Metallic Alloys for Laser Powder Bed Fusion

Laser powder bed fusion (LPBF) of metallic alloys is a transformative additive manufacturing technology that can produce net-shape components with nearly unlimited geometrical complexity and customization. This technology also brings an opportunity to develop new and modified alloys specifically for LPBF, which warrants fundamental understanding of phase equilibria, diffusion kinetics and solidification so that the dependent process variables are desensitized for buildability, and thermo-kinetic environment associated with LPBF are effectively utilized to optimize the functional properties. Experimental facility that includes gas atomization, laser powder bed fusion and a suite of microstructural and mechanical characterization will be introduced along with results that highlight the additive manufacturing of Mg- Al-, Ti-, Fe-, Ni-, and Cu-base alloys. Detailed observations of keyhole porosity, lack-of-fusion flaws and most importantly, solidification cracking during LPBF for Al-alloy are documented with respect to the alloy composition and microstructural development including grain refinement. Computational alloy design and modification strategies specific for LPBF will be discussed to expand the list of alloys available for LPBF.