A Microstructure-Properties Perspective on AM

Metals Additive Manufacturing has made great strides in the last few years, particularly with respect to laser powder bed fusion (LPBF). An overview of the capability and challenges of LPBF from a research perspective will be given. Recent results in a program to develop qualification methodologies will be summarized. Efforts to build high temperature heat exchangers will be described. The relationship between part geometry and residual stress in stainless steel will be explored. Fundamental research underpinning LPBF such as tomography to quantify defect structures, high speed visualization of keyholes, melt pools, bead-up and hot cracking will be reviewed, also high speed diffraction experiments that quantify phase change. The evolution of microstructure during rapid solidification will be compared with computer simulation results. Co-design of parts, the feedstocks and the associated printing process is essential for metals additive manufacturing to succeed over the long haul.