Controlling interdependent meso-nanosecond dynamics and defect generation in metal 3D printing
Saad A. Khairallah, Aiden A. Martin, Jonathan R. I. Lee, Gabe Guss, Nicholas P. Calta, Joshua A. Hammons, Michael H. Nielsen, K.J. Chaput, Edwin J. Schwalbach, Megna Shah, Michael Chapman, Trevor M. Willey, Alexander M. Rubenchik, Andrew T. Anderson, Y. Morris Wang, Manyalibo J. Matthews, Wayne E. King
Abstract
State-of-the-art metal 3D printers promise to revolutionize manufacturing, yet they have not reached optimal operational reliability. The challenge is to control complex laser-powder-melt pool interdependency (dependent upon each other) dynamics. We used high-fidelity simulations, coupled with synchrotron experiments, to capture fast multitransient dynamics at the meso-nanosecond scale and discovered new spatter-induced defect formation mechanisms that depend on the scan strategy and a competition between laser shadowing and expulsion. We derived criteria to stabilize the melt pool dynamics and minimize defects. This will help improve build reliability.