Microstructure and mechanical properties of a basal textured AZ31 magnesium alloy cryorolled at liquid-nitrogen temperature

A strongly basal textured AZ31 magnesium alloy were cryorolled at liquid-nitrogen temperature at various strains. The microstructure and texture of the rolled sheets have been investigated using electron backscatter diffraction (EBSD) and X-ray diffraction. The microstructural and textural evolutions of the AZ31 magnesium alloy during cryorolling have been discussed. A lot of twins were observed in the rolled sheets. The influence of strain on the twin types and variant selection during cryorolling for the magnesium alloy has been discussed quantitatively based on the orientation data collected using EBSD. The influence of the twins on the microstructural and textural evolutions for the AZ31 magnesium alloy during cryorolling has also been discussed. The mechanical properties of the cryorolled sheets were tested by uniaxial tensile tests at the ambient temperature with a strain rate 10^-3s^-1 in the tensile direction respectively along the rolling and transverse directions of the rolled sheets. The relationships between the mechanical properties and microstructure of the cryorolled sheets have been discussed in the present work. The active twinning during rolling at that cryogenic temperature has been found to play an important role in influencing the microstructure, texture, as well as the mechanical properties of the AZ31 magnesium alloy.