Crystallographic effects in intergranular corrosion of an Al-Mg alloy

The effect of grain boundary misorientation on intergranular corrosion of Al-4Mg was investigated with electron backscattered diffraction (EBSD) and profilometry of an epoxy replica of the attacked surface. It was found that grain boundaries with low misorientation (<20degrees) showed less attack than boundaries with higher misorientation. In general, low energy coincident site lattice (CSL) boundaries did not show particularly low attack, with the exception of Sigma=5 boundaries. was used to confirm the formation of Mg-rich particles at sensitized grain boundaries.