Numerical Simulation of the Molten Pool of a Powder Bed

Abstract

In this study, a numerical approach is developed to simulate the molten pool formation during the melting of a powder bed. It is based on a fluid formulation that allows taking into account the dynamics in the molten pool through the two effects of surface tension (including both 'curvature effect' and the 'Marangoni effect') and buoyancy. Additionally, the free surface is considered using an ALE method. The shrinkage of the powder layer after its melting and the change of the thermo-physical properties depending on the material state (powder or compact) are also modeled. As an application, a 3D thermo-fluid simulation of the powder bed melting is carried out. It is found that the powder layer porosity has a great effect on the molten pool morphology.