Microstructural, Mechanical and Tribological Behavior of Gravity- and Squeeze-Cast Novel Al–Si–Cu–Mg–Fe Alloy

Abstract

A novel Al–Si–Cu–Mg–Fe alloy was cast using gravity die casting and squeeze casting at low and high pressures. The micrographic analysis revealed significant variation in the grain size and phase morphologies. The high pressure employed in squeeze casting induced a compressive force on solidifying metal, which led to closure of the porosities resulting in the highest density and hardness. The differential scanning calorimetric analysis was performed from 480 to 650 °C, which demonstrated more stored energy and less amount of Al2Cu dissolution in the squeeze-cast samples. The high-pressure squeeze-cast alloy showed an enhanced strength and ductility of around 15% and 51%, respectively, than the conventional gravity casting due to grain refinement and a decrease in dendritic arm spacing. Wear resistance is highest for squeeze-casted samples at high pressure due to hard undissolved Al2Cu particles.