A novel approach to optimize mechanical properties for aluminium alloy in High pressure die casting (HPDC) process combining experiment and modelling

Abstract

Aimed at the mechanical property improvement in the high pressure die casting (HPDC) process for the aluminium alloy, two sets of shot curves (the baseline and the optimized condition) are designed to study their influence on the distributions of the ultimate tensile strength ( UTS ) and the elongation ( El ) for the as-cast ASTM tensile samples. Difference in the as-cast microstructures and defects are characterized and compared accordingly. Following the experiments, a mathematical model for the entire HPDC process is established to study the characteristics of the melt flow, heat transfer, solidification and defects formation (entrapped gas, oxides, porosities) during the HPDC process with the two above-mentioned piston shot curves are analyzed. The results have shown that the UTS and the El are improved obviously with the optimized shot profile. And the mechanism for these changes are explained in detail. This work provides a novel approach for designing and optimization of metal casting process without conducting excessive experiments and it could be transferred and applied to various alloys systems and different casting processes.