Quantitative analysis of spatter formation in Laser Powder Bed Fusion: unraveling the impact of beam shaping and multi-beam processing

In the realm of laser-based powder bed fusion processes with metals (PBF-LB/M), spatter formation serves as a crucial stability criterion. However, existing analyses often adopt a qualitative approach, hindering meaningful comparisons between processes. The quantitative investigation of the advantages of beams with non-Gaussian intensity distribution as well as multi-beam processing strategies with regard to spatter formation is still largely unexplored. To address this gap, we present an experimental setup utilizing high-speed videography and individual particle tracking to measure spatter characteristics, count size, ejection angle, and velocity, within the PBF-LB/M process conditions. The investigation deals with focused and defocused Gaussian beams, a beam with ring-shaped intensity as well as processing with two coupled Gaussian beams for the PBF-LB/M of nickel-base alloy 625.