Thermo-fluid Dynamical Simulation of Layer Build-up by Selective Laser Melting of Molybdenum and Steel

Abstract

Numerical simulations are a powerful tool to gain a fundamental process understanding of Selective Laser Melting (SLM). They allow a look into process details and to extract the influence of single process and material parameters. In this contribution a multi-physical finite element simulation model for SLM is presented. The coupled thermo-fluid dynamical model includes the absorption of laser radiation on the surface of the metal powder, conductive and convective heat transfer in the metal and the ambient atmosphere as well as melting, solidification, evaporation, and condensation processes. The model is applied to an analysis of the influence of process parameters on the process and the processing result in SLM of molybdenum and steel. It shows the material specific process characteristics as well as the influence of power and energy input on the surface morphology in layer build-up. The predictions of the simulation model are in good accordance with experimental metallographic data.