Superplasticity and Deforming Mechanism of As-extruded AZ81 Magnesium Alloy

Superplastic behaviors and deformation mechanism of as-extruded AZ81 magnesium alloys were investigated. The material was at first treated through hot-extrusion, and then superplastic tensile tests were performed under various temperatures and initial strain rates. Strain- rate sensitivity was calculated for this alloy. Through the observation and comparison of steady flow stress under different temperatures, the reasons for the change in superplastic deformation mechanisms were analyzed. The deformation mechanism is grain boundary sliding, while the accommodating mechanism is cavity nucleation and fracture.