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

During the laser-powder bed fusion 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 in 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 that 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 intensity. Also, significant differences are noticed between the different alloys.