Conclusions
In the present work, an attempt was made to study the effect of strain
reversal (CW-CCW) deformation on the microstructure and hardness
properties of Al-2.5%Mg alloy. It was found that in Al-2.5%Mg, the
evolution of the ultrafine structure follows the similar trend in
microstructure analysis when deformed through two deformation
techniques, with the exception during high strains where the fraction of
HAGBs was found strikingly less as compared to its counterpart during
strain reversal deformation. Hardness homogeneity was not observed for
Al-2.5%Mg where the hardness at the centre regions was observed to be
lesser than the edge regions with exceptionally less hardness at centre
for strain reversal specimens at higher strains. The phenomenon behind
low HAGBs in strain reversal deformation is predicted to be due to back
stress due to strain reversal, which ultimately hinders the formation of
dislocations formed by F-R source of dislocation