| Multi-physics coupling is a key characteristic of selective laser melting (SLM), involving complex physical phenomena such as heat transfer, phase transition, molten pool flow, and grain growth, which raise great challenges for quality control. In this paper, we propose a computational framework integrating the discrete element method (DEM) and phase-field method (PFM) to achieve high-fidelity numerical simulation of SLM. Firstly, the powder spreading process is simulated by DEM, and the effect of powder spreading parameters on the quality of the powder-bed layer is discussed. Secondly, a non-isothermal phase-field model including heat-fluid-microstructure coupling is presented, which is verified by the benchmark case of the gas-liquid two-phase flow behavior. In addition, the influence of recoil pressure and Marangoni effect on the molten pool behavior is studied. Finally, the whole process simulation of powder spreading and laser scanning of single layer is realized, which reproduces the phenomena of molten pool flow, solidification and grain evolution during SLM process. |
