Improved tensile properties of AZ31 Mg alloy subjected to various caliber-rolling strains

A multi-pass caliber rolling has attracted attentions as an alternative to severe plastic deformation processes. The present study enhanced strength and ductility of AZ31 Mg alloy simultaneously through the application of caliber rolling. The improving trends in tensile properties were interpreted with various caliber-rolling strains. The oval/circular-shaped calibers imposed a high plastic strain at the center of cross-section, leading to effective grain refinement to submicron scale. This work also confirmed the texture randomizing effect of caliber rolling. Such microstructural evolutions gave rise to the fabrication of high-strength material. Moreover, the caliber-rolled AZ31 Mg alloys exhibited an improvement in ductility as compared to the as-received sheet-rolled material. This was discussed in terms of activation of non-basal slip systems and suppression of mechanical twinning. This study successfully proved the possibility of caliber rolling to produce a bulk Mg rod with enhanced tensile properties. (C) 2019 Published by Elsevier B.V. on behalf of Chongqing University.