Enhanced superplasticity in equal-channel angularly pressed Sn–5Sb alloy

The superplasticity of a fine-grained Sn–5 wt.% Sb alloy, processed by equal-channel angular pressing (ECAP), was investigated by impression testing in the temperature range of 298–370 K. The deformation response of the ECAPed material with a grain size of 2.5 μm conforms to regions I, II and III, typical of superplastic behavior. In region II, the strain rate sensitivity indices of 0.42–0.60 and activation energy of 42 kJ mol−1 are indicative of a superplastic deformation behavior dominated by grain boundary sliding.