HIGH-FIDELITY MULTI-PHYSICS MODELING OF MOLTEN POOL DYNAMICS IN METAL ADDITIVE MANUFACTURING

Abstract

The molten pool flow in metal additive manufacturing plays a crucial role in defect formation, which can compromise the mechanical properties of manufactured parts. In this study, we develop an evaporation model that considers the gas flow structure and material composition, and integrate it into a multi-physics thermal-fluid flow model that employs the Volume of Fluid in the Finite Volume Method and the ray-tracing method to capture free surfaces and track laser reflections within a keyhole. We simulate the keyhole pore formation process to investigate the mechanisms behind it and adopt a solute transport model to predict the element concentration distribution. Additionally, we develop a Thermoelectric Magnetohydrodynamic (TEMDH) model that integrates the electrodynamic model with the Seebeck effect into the multi-physics thermal-fluid flow model. With this high-fidelity multi-physics thermal-fluid flow model, the influence of metal evaporation and external magnetic fields on the molten pool dynamics are synthetically studied, which will give guidance to the metal additive manufacturing process.