Factors influencing superplastic behavior in a magnesium ZK60 alloy processed by equal-channel angular pressing

Processing by equal-channel angular pressing was used to refine the grain size of a magnesium ZK60 alloy to ∼0.8 μm and introduce a superplastic capability. Superplastic elongations up to >1000% were achieved at temperatures of 450 and 473 K but the superplastic behavior was lost at 493 K because of grain growth. The strain rate sensitivity under optimum superplastic conditions was measured as ∼0.5 which is consistent with conventional superplastic flow.