Texture modification and mechanical properties of AZ31 magnesium alloy sheet subjected to equal channel angular bending

Analysis of the recently proposed equal channel angular bending (ECAB) process is provided on thin hot-rolled AZ31 magnesium alloy sheets. In particular, effects of deformation temperature and strain path on the texture evolution and mechanical properties are systematically investigated under single pass ECAB at various temperatures and multi-pass ECAB process that involves changes in strain paths. It is found that simultaneous activation of multiple twinning types is successfully introduced during ECAB, which results in obvious tilted component of basal texture. Attributed to the domination of extension twins, weaker basal textures are detected after both single pass ECAB at 150 degrees C and three cross passes ECAB at 200 degrees C. After annealing, the basal texture is further weakened via twin-related recrystallization and the annealed microstructure is featured with mixture of basal and non-basal orientated grains. Additionally, the effect of grain orientation on the mode of plastic deformation and the roles of grain orientation and grain boundary on the local strain accommodation are coherently studied. This study reveals that over 60 % increase of uniform elongation with marginal reduction of tensile strength less than 5 % can be achieved for single pass ECAB at 150 degrees C and three cross passes ECAB at 200 degrees C, which is the result of larger fraction of grains favored with extension twinning and better local strain accommodation. (C) 2021 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

This study provides an analysis of the ECAB process on thin hot-rolled AZ31 magnesium alloy sheets, investigating the effects of deformation temperature and strain path on texture evolution and mechanical properties. The study reveals that during ECAB, multiple twinning types are activated simultaneously, leading to a tilted component of basal texture. It also shows that an increase in uniform elongation over 60% with a marginal reduction of tensile strength less than 5% can be achieved through ECAB, attributed to larger fraction of grains favored with extension twinning and better local strain accommodation.