A coupled EBSD/TEM study of the microstructural evolution of multi-axial compressed pure Al and Al-Mg alloy

The effects of multi-axial compression (MAC) on the microstructural evolution of pure Al and Al-4 wt%Mg alloy were investigated by means of TEM and EBSD techniques. It shows that the addition of high concentration solute Mg to Al changes the grain refinement process. Most importantly, new high-angle grain boundaries form via different mechanisms for pure Al and Al-4 wt%Mg alloy: orientation splitting for pure Al and shear banding at low strain and orientation splitting at high strain for Al-4 wt%Mg alloy. In addition, the solute Mg can hinder the dislocation slip and retard the dynamic recovery during the deformation process. Consequently, the Al-4 wt%Mg alloy exhibits a slower misorientation evolution compared to pure Al, and obvious differences in hardness and microtexture evolution exist between pure Al and Al-4 wt%Mg alloy.