On the Controversy about the Presence of Grain Boundary Sliding in Mg AZ31

Abstract

Highly-textured, rolled AZ31 sheet material shows a significant drop in the plastic anisotropy (r-value; r=ew/et) in tension between 25°C and 200°C. This behavior was initially explained as a result of the increased activity of non-basal slip with increased temperature. Other authors suggested, however, that the mechanism responsible for this phenomenon was the activation of grain boundary sliding (GBS). Here, in-situ tensile tests have been carried out in an SEM at various temperatures in order to obtain further evidence of the role of GBS during moderate to high temperature deformation of Mg alloys, which remains highly controversial.