Microstructure development and related mechanical behavior of the ZEW200 Mg alloy processed by differential speed rolling and equal channel angular pressing

Abstract

The present work investigates the influence of shear deformation on microstructural-texture and mechanical behavior of ZEW200 Mg alloy sheets. For the introduction of extra shear deformation during thermomechanical processing, the separate effect of differential speed rolling (DSR) and equal channel angular pressing (ECAP) were analyzed. The results were compared with the microstructure and mechanical behavior of equal speed rolled (ESR) ZEW200 sheets. No significant texture changes were observed after the utilization of DSR, while ECAP processing was effective in changing the character of the texture and reducing the texture intensity. The large yield stress asymmetry observed in the rolled sheet is strongly reduced in the ECAP processed sheets. Results showed the potential to use shear deformation to modify the crystallographic texture via the profuse activation of {10-12}<10-11> extension twins. The presence of a large twin fraction of the microstructure modified the work hardening behavior of the processed sheets due to the further activation of basal slip. The application of extra shear deformation to tailor the texture during processing is, therefore, an alternative to optimize the deformation behavior of already formable Mg alloys.