Evaluating the Plastic Anisotropy of AZ31 Using Microscopy Techniques

The tensile deformation mechanism of a rolled AZ31 alloy at 50°C, 150°C, and 250°C was investigated by a combination of in situ tensile testing, electron backscatter diffraction analysis, and ex situ atomic force microscopy analysis. With increasing temperature, there was a significant difference in the activity of the various deformation modes, along with a decrease in the plastic strain ratio. Extension twinning was only observed at 50°C, while at higher temperatures, a combination of basal and prismatic slip accounted for a large percentage of the observed deformation activity. Prismatic slip was prevalent at all testing temperatures and exhibited increased activity with increasing temperature. The activity of pyramidal 〈c + a〉 slip increased from 50°C to 150°C and then decreased at 250°C. Ex situ atomic force microscopy measurements suggested that the contribution from grain boundary sliding to the overall strains increased with increasing temperature. Overall, the in situ experiments combined with atomic force microscopy suggested that grain boundary sliding contributed more to the reduction in plastic strain ratio with increasing temperature than nonbasal slip activity.