Influence of texture and grain size on work hardening and ductility in magnesium-based alloys processed by ECAP and rolling

Equal channel angular pressing (ECAP) and large-strain hot rolling (LSHR) are widely used methods for refining the grain size in magnesium alloys. The hardening capability of the processed materials confers the resistance to develop tensile mechanical instabilities, therefore controlling ductility. In this work various magnesium alloys were processed using ECAP, LSHR and annealing treatments in order to control the texture and the grain size. Emphasis was laid upon the influence of these factors on work hardening behavior and dynamic recovery. In addition to the direct effect of texture through the change in the orientation factor for basal and prismatic slip, effects were found on dynamic recovery and the appearance of stage II of work hardening. The grain size refinement causes a strong decrease in the hardening rate. A contribution of grain boundary sliding to deformation gives a plausible explanation of these results. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.