Numerical Simulation of Flow Field of Mg-Y-Sm-Zn-Zr Alloy Formed by Selective Laser Melting

Abstract:

A powder-scale three-dimensional model of the selective laser melting (SLM) process for Mg-3.4Y-3.6Sm-2.6Zn-0.8Zr alloy was established by the discrete element method and the finite volume method, and the effects of laser power, scanning speed and laser line energy density on the fluid flow in the molten pool were simulated. The problems of metal melting, fluid flow and solidification and forming process in the molten pool were analyzed. Results show that the effects of increasing the laser power or decreasing the scanning speed on the solute flow in the molten pool are essentially the same. At a certain scanning speed, the maximum fluid flow rate is 4.914 m/s when the laser power is 100 W. The recoil pressure due to the evaporation of the molten liquid at higher molten pool temperatures leads to the depression of the molten pool.