Superplastic Properties and Microstructure of Friction Stir Welded Joints of Zn-22wt.%Al Alloy
Deformation mechanism of room-temperature superplasticity in Zn-22wt%Al alloy was investigated by the direct observation during deformation. It was revealed that the dominant deformation mechanism of room-temperature superplasticity was grain boundary sliding. Also, superplastic properties and microstructure of friction stir welded Zn-22wt.%Al alloy were investigated, where Friction Stir Welding (FSW) has received a great deal of attention as a new solid-state welding technique. A sound jointing material was obtained successfully, and extremely fine and equiaxed grains were created in the stir zone. In addition, it was indicated that superplastic forming of the FSWed Zn-22wt.%Al alloy could be feasible. However, the tensile strength and elongation of the joint at room temperature were lower than that of the base material.
N. Ohno and T. Uehara
T. Tanaka et al., "Superplastic Properties and Microstructure of Friction Stir Welded Joints of Zn-22wt.%Al Alloy", Key Engineering Materials, Vols. 340-341, pp. 1417-1424, 2007