G040035 Effect of Friction Stir Processing on Mechanical Behavior of Zn-22A1 Superplastic Alloy

Friction stir welding (FSW) is a relatively new solid-state joining process primarily for aluminum alloys. FSW has been generating interest because of its association with friction stir processing (FSP), a new technique that essentially employs FSW tooling. FSP is being explored as a thermo-mechanical processing technique to transform a heterogeneous microstructure into a more homogenous microstructure. However, very little information is available regarding FSP characteristics of superplastic alloys. In past studies we discussed the trials of Friction Stir Processing (FSP) on Zn-22A1 superplastic alloy. Specially, the effects of FSP parameters on strength anisotropy and superplastic properties had been researched at room temperature. In this study we discuss the changes of microstructures of Zn-22A1 superplastic alloy due to FSP and how the superplastic properties react at high temperature.