Clarification of the Fracture Location in Friction Stir Processed AZ31 Mg Alloy through Examination of Globe and Miniature Specimens

Sections in a friction stir processed AZ31 Mg alloy were extracted primarily from specific positions corresponding to the stir zone to explore the tensile responses of mini-regions. According to the orientation distribution examined by the thin film X-ray method, basal planes in the stir zone tended to lie in a valley shape; meanwhile, a banded structure could also be recognized in the stir zone. The variation of basal plane alignment affects the deformation resistance and tensile ductility so that the tensile responses behaved as a function of locations in the stir zone. Combining sections with variant deformation resistance, the yield stress of a global specimen was similar to that of the mini-region with the minimum deformation resistance. With locations of low fracture resistance, the banded structures in the stir zone strongly affected the fracture feature and tensile ductility of each friction stir processed mini-region. The banded structures in the stir zone were also responsible for the reduction in the ductility of the globe specimen. [doi:10.2320/matertrans.M2012050]