Simulation of temperature field and stress field of selective laser melting of multi-layer metal powder

摘要

In this study, the temperature field and the stress field of a multilayer metal powder were investigated using the point exposure scanning mode. A three-dimensional thermo-structural coupling model was established by using the finite element method, and the multi-layer multi-track SLM process was simulated. The model considered the latent heat of phase change, physical parameters with temperature change, convective heat transfer, and so on. The temperature, molten pool and stress changes at different positions were analyzed, and finally the residual stress distribution of the model was obtained. The residual stress distribution on the upper surface of the SLM fabricating part under point exposure scanning had strong volatility, which was different from continuous exposure scanning. The maximum residual stress appeared at the end of the first track in the first layer. The reliability of the numerical simulation was verified by the size of the molten pool in the experiment.