Relationship between deformation behavior and microstructural evolution of friction stir processed Zn–22 wt.% Al alloy

Zn–22 wt.% Al alloy, which exhibited room-temperature superplasticity, was refined by friction stir processing (FSP) and its deformation behavior was investigated and compared with that of superplastic Zn–22 wt.% Al alloy. The deformation mechanism at room temperature was the same in both alloys. However, at a high strain rate the elongation-to-failure of the friction stir processed material was significantly larger than that of the base material. It was considered that the microstructural evolution due to FSP influenced the deformation behavior of the friction stir processed material.