Finite Element Simulation of Selective Laser Melting process considering Optical Penetration Depth of laser in powder bed

Abstract

A three dimensional finite element model (FEM) is introduced in this work in order to simulate the melt pool size during the Selective Laser Melting (SLM) process. The model adopts the Optical Penetration Depth (OPD) of laser beam into the powder bed and its dependency on the powder size in definition of the heat source. The model is used to simulate laser melting of a single layer of stainless steel 316L on a thick powder bed. The results of the model for the melt pool depth are validated with the experimental results. The model is then used to predict the effect of different scanning speeds on the melt pool depth, width, and length. The results showed that the melt pool size varies from the beginning of a track to its end and from the first track to the next. The melt pool size, however, reaches a stable condition after a few tracks. This concept was used to simplify the process modeling in which reduces the computational costs.