Study of spatter ejections during laser-powder bed fusion process for aluminum alloys

Abstract

During L-PBF process on aluminum alloys, instabilities such as spatter ejections result from the laser-matter interaction. These spatters create a variety of defects and affect the mechanical properties of the final parts. To help understanding this phenomenon, a global method was developed, combining experimental study and image analysis. This system provides statistic information on spatter population (radius, velocity, direction and emission rate) and the idea of pollutant spatter is defined. Four aluminum alloys are compared. The results show the oxygen content in the fabrication chamber has no effect on the spatter ejection dynamic. The spatter velocity, angle of ejection and size increase with the intensity. Also, significant differences are noticed between the different alloys.

Miniature laser powder bed fusion system for in situ synchrotron x-ray micro-computed tomography experiments at the European Synchrotron Radiation Facility

“…Thus, much research effort has been made to provide a fundamental understanding of the mechanisms leading to defect formation in additively manufactured objects. High-speed optical cameras were first used for in situ process monitoring to estimate the density of spatters, [1][2][3][4][5] but this approach suffers from a major limitation since only the top surface can be observed. This limitation was recently overcome with the development of different L-PBF replicators [6][7][8][9][10] allowing time-resolved x-ray images to be collected during 3D printing.…”