3D X-ray microtomography and mechanical characterization of corrosion-induced damage in 7075 aluminium (Al) alloys

We report on the 3D microstructure, composition and mechanical properties in the corroded region of Al (7075-T651) alloy corroded in 3.5 wt.% NaCl. Visualization and quantification of the microstructure was conducted using X-ray tomography with a focus on change in dimensions of pits with increasing corrosion. The variation of tensile strength with corrosion and its relationship with microstructure was also studied. Compositional analysis using EDS, coupled with nanoindentation, showed a partially corroded region adjacent to the corrosion product layer.