Optimization of Process Parameters for Unidirectional Solidification of Magnesium Alloy

摘要

The unidirectional solidification process of magnesium alloy needs to establish a specific temperature gradient in casting mold, the direction of crystal growth and heat flow are in the opposite direction in the unidirectional solidification. The process can better control the grain orientation, and eliminate the horizontal grain boundary to obtain excellent performance of magnesium alloy. In this paper, Numerical simulation by FEM (finite element method) is employed to calculate the temperature field according to the actual process, considering the factors of pulling speed, cooling time, cooling intensity. Numerical solution is a complex nonlinear problem involving the moving boundary condition when considering the pulling velocity factor. The macro analysis results of temperature field are inducted into the microstructure analysis by the undercool value in the chilled shell. The microstructure obtained by PFM (phase field method) is in agreement with the actual pattern by the optical microscope observation.