Achieving high strain rate superplasticity in Mg–Y–Nd–Zr alloy processed by homogenization treatment and equal channel angular pressing

Homogenization treatment and equal channel angular pressing was applied to Mg–Y–Nd–Zr alloy cast ingot. Uniform grains with a grain size of ~1.5 μm and spherical secondary-phase preferentially located at the grain boundaries were obtained. Excellent high-strain rate superplasticity of 860% and 960% was achieved at 500 °C, 1×10−1 s−1 and 475 °C, 2×10−2 s−1, respectively, for the first time such a high-strain rate superplasticity was achieved in magnesium alloys processed by ECAP. The maximum elongation of 1120% was achieved at 475 °C, 3×10−3 s−1. They were attributed to the thermal stability of uniform fine-grain microstructure and the coordination function of secondary-phase.