The Role of Deformation Modes on Ductility and Dynamic Recrystallization Behavior of AZ31 Mg Alloy at Low Temperatures

Abstract

Tensile ductility and dynamic recrystallization of AZ31 (Mg-3Al-1Zn) alloy samples were investigated at the temperature range of 25°C–200°C. Samples were cut from a strongly textured, hot rolled AZ31 plate from three different orientations in order to activate alternate deformation mechanisms during uniaxial tensile loading. Dynamic recrystallization (DRX) behavior was found to be highly dependent on the active deformation modes at temperatures between 100°C and 200°C, where non-basal slip mechanisms (prismatic and pyramidal ) retards DRX whereas basal slip promotes DRX. The final microstructure and elongation to failure vary with active deformation modes at moderately elevated temperatures (>50°C), while at room temperature elongation to failure seems to be insensitive to the deformation modes. There is a significant indication that twinning initiated shear localization and induced an earlier fracture at elevated temperatures. More homogenous deformation until necking was observed when prismatic slip was the main active deformation mode.