Correlation of spatter behavior and process zone formation in powder bed fusion of metals

Abstract

In powder bed fusion of metals by a laser beam (PBF-LB/M) spatters evolve due to evaporation phenomena within the interaction zone of the laser-beam and material. The evaporation is of high importance for the evolution of a melt depression in the process zone. We use high-speed stereoscopic imaging to measure the three-dimensional (3D) time-resolved spatter trajectories. The statistical spatter behavior is correlated with the transition from heat conduction mode into evaporation dominated mode in the interaction zone and its geometry. The results indicate a high potential to use statistical measures of the 3D spatter trajectories for quality assurance in PBF-LB/M.