Numerical simulation on molten pool flow of Inconel718 alloy based on VOF during additive manufacturing

In this paper, the discrete element method is used to establish the model of the powder bed. The numerical simulation model is established by the finite volume method. The results shows that the heat diffusion is relatively slow when the laser act on the powder bed, which result in a small heat-affected zone of the powder bed and the base metal. The molten pool is a semi-elliptical shape, and the cladding layer formed after the molten pool solidifies is flat. As the heat source get closer to a certain point on the scanning path, the flow direction of the molten pool became uniform gradually from random at the beginning. The initial temperature of the powder bed become higher when the second track is deposited, and the depth of the molten pool is deeper than that of the first track. The second cladding layer overlap the first one well. The flow direction of the molten pool at a fixed point gradually change from disorder to uniform with the approach of the heat source. The flow direction of the molten pool in the remelting part always remain uniform.