3D tracking velocimetry of L-PBF spatter particles using a single high-speed plenoptic camera

Abstract

Particle spatter is an unavoidable by-product of the Laser-Powder Bed Fusion (L-PBF) process, as the high intensity of the incoming laser beam generates high vapor fluxes on the meltpool, allowing metal particles to be ejected into the process environment. This is detrimental to the final manufactured part, as it risks the incorporation of defects. It is therefore important to study this spattering behavior and to apply the knowledge gained to further improve the L-PBF process. This work introduces the use of a high-speed plenoptic camera to acquire 3D spatter particle trajectories generated via L-PBF line tracks. Spatter particles are tracked in the volume above the laser-metal interaction zone at 1000 fps and their velocity calculated. It is found that the calculated speeds of the spatter particles are within the expected range for this process, and that the behavior is a complex 3-dimensional process.