Melting pool simulation of 316L samples manufactured by Selective Laser Melting method, comparison with experimental results

Selective laser melting method (SLM) is one of the main additive manufacturing method to manufacture metallic parts from powders. Simulation of SLM method by finite element method (FEM) has several computational problems, since high temperature gradient, small melting pool, high cooling rate and very small thickness of each layer. In this study, manufacturing of a sample of 316 stainless steel is simulated by FEM and temperature variation as a function of time and coordinates is obtained. Thermo-physical properties of each phase, including powder, melted and solid, are considered temperature dependent. The melting pool is experimentally determined for each track and layer. It is shown that each track is overlapped the precedent track. Melting of a new layer leads to partial melting of the previous manufactured layer. It is shown experimentally that the keyholes are created at the end of each track due to the pause time, which increase the input energy density. Obtained temperature distribution across sample and time will be used to determine the residual stress and strains and then mechanical properties of the manufactured sample can be characterized.