Thermo-Fluiddynamic Modeling of Laser Beam-Matter Interaction in Selective Laser Melting

Selective Laser Melting (SLM) offers great potential for future manufacturing technology. In order to extend its applicability for the processing of high melting materials like molybdenum fundamental process understanding is required. This can be obtained by multi-physical simulations that allow a look into the process. In this contribution a thermofluiddynamical simulation model for laser beammatter interaction based on Comsol Multiphysics is presented and applied for an analysis of the SLM process. The model includes the absorption of laser radiation, conductive and convective heat transfer as well as melting, solidification, evaporation and condensation processes. Based on the model a material specific comparison of SLM of steel and molybdenum is performed. Whereas for steel a long melt pool and a significant amount of evaporation is found, for molybdenum the melt pool is restricted to the size of the laser beam and no evaporation is observed.