High strain rate superplasticity in a continuously recrystallized Al-6%Mg-0.3%Sc alloy

Abstract

The superplastic properties of a cold-rolled Al±6Mg±0.3Sc alloy were studied at temperatures between 450 and 5608C and strain rates between 10⁻⁴ and 100⁰ s⁻¹. The alloy was observed to exhibit super- plasticity over wide temperature (475±5208C). It was found that the addition of Sc to Al±Mg alloys resulted in a uniform distribution of fine coherent Al₃Sc precipitates which effectively pinned subgrain and grain boundaries during static and dynamic recrystallization. In this paper, the microstructural evolution during superplastic deformation was systematically examined using both opti- cal and transmission electron microscopy