Superplastic Behavior and Microstructural Evolution in a Commercial Mg-3Al-1Zn Magnesium Alloy

Abstract

Superplastic behavior and microstructural evolution in a commercial Mg–3Al–1Zn magnesium alloy were investigated at temperatures between 623 K and 723 K and strain rates between 10⁻⁵ and 10⁻³ s⁻¹. Grain refinement was obtained in the test alloy due to the dynamic recrystallization during an initial stage of tensile test. As a result, the alloy exhibited good superplasticity at all strain rates and temperatures, and a maximum elongation of 314% was obtained. The results of optical microscopy and SEM revealed that the dominant deformation mechanism was grain boundary sliding, and the dynamic recrystallization was the accommodated mechanism for the deformation.