Effect of microstructure on tensile and compressive behavior of WE43 alloy in as cast and heat treated conditions

The influence of heat treatment on the microstructure, tensile and compressive properties and failure mechanisms of WE43 alloy is studied. The eutectic phase is dissolved into the α-Mg phase and the grain size is refined in the heat treated alloy. Heat treatment improves the tensile yield and ultimate strengths by 40% and 53%, respectively. The compressive yield and ultimate strengths of heat treated alloy are also 55% and 23%, respectively, higher compared to the as-cast alloy. Compressive characterization is also conducted at high strain rates. The energy absorption capability of WE43-T5 specimens is higher than the as-cast WE43 specimens at all strain rates investigated in this work. Failure initiates with cracks in the eutectic phase in the as-cast alloy. These cracks grow through the grain to result in transgranular fracture. The absence of eutectic mixture in heat treated alloy results in grain boundary sliding and crack initiation at triple junctions. The crack propagation is delayed in the absence of eutectic precipitates, which improves the mechanical properties of the heat treated alloy.