Texture-Induced Corrosion Resistance of Dissimilar AA7204/AA6082 Friction Stir Welded Joints

The quasi in situ EBSD test was applied to study the effect of grain orientation on corrosion behaviors of the thermomechanically affected zone I (TMAZ I) of dissimilar AA6082/AA7204 friction stir welding (FSW) joints in this work. The results show that the structure with grain orientation close to the brass texture ({110}<112>) has excellent corrosion resistance, which contributes to the better corrosion performance of the TMAZ I of the 7204-AS joint than the 7204-RS joint. Furthermore, the brass texture around by S texture ({213}<364>) in the TMAZ I of the 7204-AS joint is slightly corroded, and the orientation of the remaining structure is closer to the ({110}<112>) than before, which indicates that the corrosion, like deformation, is carried out alongside the {110} plane for the structure with grain orientation near {110}<112>. Those findings could provide new insight into the designed FSW joints and improve the corrosion resistance of the wrought aluminum alloy.