Mesoscopic simulation model of selective laser melting of stainless steel powder

A 3D mesoscopic model is developed to simulate selective laser melting processes using the ALE3D multi-physics code. We study the laser-induced melting of a random bed of stainless steel 316 particles on a solid substrate (1000 μm × 300 μm × 50 μm) and its solidification into either a continuous track or a discontinuous track as a result of Plateau-Rayleigh instability. Our approach couples thermal diffusion to hydrodynamics and accounts for temperature dependent material properties and surface tension, as well as the random particle distribution. The simulations give new physical insight that should prove useful for development of continuum models, where the powder is homogenized. We validate our approach against the experiment and find that we match the main laser track characteristics.