Microstructure and mechanical properties of Mg-Al-Zn alloy sheets severely deformed by asymmetrical rolling

By applying a high ratio of the circumferential velocities between the upper and lower rolls in asymmetrical rolling, a very fine grain size of 1.4 mu m could be achieved after a single pass of 70% thickness reduction. Basal fiber texture was notably weakened during the rolling. The rolled sheets exhibited high yield stresses over 300 MPa and a maximum elongation of 35%. Their Hall-Petch relation was compared with those for the conventionally rolled and equal channel angular pressing processed AZ31 alloys. (c) 2006 Published by Elsevier Ltd. on behalf of Acta Materialia Inc.