Analysis of Surface Layer Microstructure and Formation of Die Casting

Based on analysis of the surface layer microstructure of samples obtained from a plate die casting, three characteristics of surface layer microstructure including thick and fine chilled microstructure, a small amount of chilled microstructure and no chilled microstructure, were observed. The formation reasons of microstructures with three different characteristics were discussed by simulating filling and solidification process for the plate die casting. The results indicate that the mode of collision between filling liquid and die surface as well as the solidification sequence have important effects on the formation of surface layer microstructure.