The microstructure prediction of magnesium alloy crystal growth in directional solidification

Directional solidification process can better control the grain orientation and eliminate the horizontal grain boundary, so excellent performance of alloy can be achieved by it. In the paper, the macro and micro analysis were coupled to predict the microstructure growth of magnesium alloys in directional solidification process. FEM (finite element method) was used to calculate undercooling temperature, by which the macro analysis results were coupled into the micro analysis. Phase-field method (PFM) offers the prospect of carrying out realistic numerical calculation on dendrite growth in metallic systems, and it was employed to calculate real dimension of magnesium alloy microstructure in directional solidification. Different magnitude values of anisotropy that predicted the columnar dendrite evolution were calculated. Quantitative comparison of numerical simulation results to the experiment analysis were carried out. The microstructure obtained by PFM is in good agreement with the actual pattern by the optical microscope observation.