Characterization of Microstructure and Shrinkage Porosity of a Semi-Solid Metal Slurry in Gravity Die Casting

摘要

Current aluminum automotive parts such as wheels, engine and transmission components are produced by tilted gravity die casting for control gas porosity. But, there are still problems resulting in inefficient production: shrinkage porosity, microstructure size and uniformity. Shrinkage porosity is one of the major issues which affects mechanical properties such as strength and elongation in tilted pour permanent mold. Recent work using slurry casting technique has shown potential in gravity sand casting. Results show that the casting parts have complete filling at low solid fractions and the casting yield is also higher than conventional gravity sand casting. This paper extends important work for potential industrial applications in gravity die casting: microstructure size, uniformity, solid fraction control for micro shrinkage level.