Achieving Superior Superplasticity in a Mg-6Al-Zn Plate via Multi-pass Submerged Friction Stir Processing

摘要

A large-scale Mg-6Al-Zn plate was prepared by multi-pass submerged friction stir processing (M-SFSP) and its superplastic deformation behavior was investigated. The maximum elongation of 467%, 332% and 421% was attained for the samples oriented in the processing direction (PD), 45 degrees tilted toward the PD, and transverse direction (TD), respectively, when deformed at 623 K and a strain rate of 1 x 10(-3) s(-1). This was attributed to the homogeneous and fine-grained structure with mostly high-angle grain boundaries facilitating the prevalent deformation mechanism of grain boundary sliding, along with the weakened texture and dynamic recrystallization during hot deformation.

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