Two-fluid model to simulate metal powder bed fusion additive manufacturing

Abstract

This paper reports our simulations of the metal powder fusion additive manufacturing process based on a two-fluid model. In simulations of metal behavior in which heat is applied by high-density energy sources (e.g., laser or electron beam), the aspects that need to be correctly modeled include boiling and evaporation, as well as melting and solidification. The potential of the two-fluid model to clarify numerous physical phenomena—deep penetration, plume generation, spatter generation due to interfacial pressure differences between gas and liquid phases, and the transport of spatter with high-speed-plume flow—are shown from a perspective that departs from conventional interpretations. This paper compares and discusses the results of simulating the penetration and width of single beads and experimental results.

Keywords

• additive manufacturing
• two-fluid model
• evaporation
• plume
• spatter
• heat counterflow
• knudsen layer