Improving the defects and mechanical properties via secondary loading in a squeeze casting heat-treated Al–Cu alloy

Defects are prone to form during solidification in Al–Cu alloy squeeze castings, especially at locations with significant differences in wall thickness. This work developed a secondary loading technique during squeeze casting to solve this problem. First, the finite element simulation method predicted the defect location in an Al–Cu alloy during squeeze casting. The application of secondary loading helped the alloy melt solidify under pressure and eliminate shrinkage porosity defects caused by solidification shrinkage. Subsequently, T6 heat treatment was performed to further improve the mechanical properties of the casting without solidification defects. The uniform distribution of θ′ nano precipitates in the casting was observed, increasing strength. This study aims to eliminate casting defects during squeeze casting to obtain high-performance castings.