Texture and mechanical properties of ultrafine-grained Mg–3Al–1Zn alloy sheets prepared by high-ratio differential speed rolling

Abstract

Mechanical properties and textures of the ultrafine grained (UFG) Mg–3Al–1Zn (AZ31) alloy with a mean grain size of 1μm produced by high-ratio differential speed rolling were investigated. The resulting material exhibited high strength and relatively high ductility at ambient temperature. The high strength was attributed to grain-size and texture strengthening, while the high ductility was attributed to suppression of inhomogeneous twinning and increased strain-rate-sensitivity. The rolling temperature and the amount of shear strain accumulated during HRDSR affected the basal texture intensity and the rotation angle of the basal poles. Bimodal grain-size distribution obtained by annealing the UFG AZ31 at 573K for a short time period resulted in considerable improvement of uniform elongation.