Anisotropy in dynamic recrystallization behavior of AZ31 magnesium alloy

Abstract

Deformation behavior as well as microstructural evolutions of a rolled AZ31 magnesium alloy with and without pre-existing extension twins were studied using compression tests which performed along different orientations at a temperature range of 25–350 °C. The results implied that the initial texture not only influence the evolution of flow stress, but also change the size and fraction of recrystallized grains. In contrast to samples parallel to rolling and transverse directions, compression along normal direction resulted in a respectful softening at 150 °C. The largest size and fraction of new grains at 250 °C were recorded after deformation along rolling direction, while the maximum flow softening was observed during deformation along normal direction. The anisotropy in microstructural evolutions was still retained at 350 °C. Pre-existing twins could reduce the anisotropy of material in respect of flow stress as well as DRX progression, where TD sample showed the lowest DRX fraction at 250 °C. Quaternion misorientation data obtained from EBSD analysis of pretwinned material implied that initial texture could not significantly influence final texture. A different misorientation distribution was realized after deformation of pretwinned material along ND and RD directions.

Keywords

• Slip
• Recrystallization
• Grain size
• Growth
• Twin