The development of superplastic ductilities and microstructural homogeneity in a magnesium ZK60 alloy processed by ECAP

An extruded ZK60 magnesium alloy was processed by equal-channel angular pressing (ECAP) and then tested in tension at elevated temperatures. The results show the alloy is superplastic at a testing temperature of 473 K with an optimum ductility of ∼1310% when using an initial strain rate of 2.0 × 10−4 s−1. The results demonstrate that optimum superplasticity is achieved at intermediate strain rates and there are decreases in the elongations to failure at both faster and slower strain rates. Microhardness measurements were taken both on the cross-sectional plane and along the axial direction after processing by ECAP. These measurements show the alloy is essentially homogeneous in the as-pressed condition.