Nathan Kistler, Application Engineer, LPW Technology Inc
As metal Additive Manufacturing (AM) moves from research and development to production scales, the requirement for stable and predictable materials becomes paramount. Many of the alloys being used in powder bed fusion have not been developed for the process, and our understanding of benign or detrimental elements from conventional processes do not necessarily apply. Presented are several case studies which detail the work to understand material response and which elements in which alloy systems are to be controlled, as well as cases of new contamination screening techniques and the importance of supplier evaluation. Specifically, this includes investigations on: reducing micro-cracking in Ni superalloys, the influence of residual elements on micro-cracking of maraging steel, the influence of minor composition variations on mechanical properties of CoCr, and the use of X-ray CT and SEM imaging to detect contamination in powder.