Role of subgrain stripe on the exfoliation corrosion of Al-4.6Mg-3.1Zn (wt.%) alloy

The role of subgrain stripe on the exfoliation corrosion behaviour in the Al-4.6 wt%Mg-3.1 wt%Zn alloy is revealed. The slight difference in the Volta potential distribution between the subgrain stripes and normal grains indicates that the selective corrosion in the subgrain stripes is not relevant to the electrochemical factor. Furthermore, the difference in the microstress state between two sides of the subgrain stripe boundary indicates a stress mechanism cooperate with the anodic dissolution mechanism is worked during the expansion of the selective exfoliation corrosion.