The propagation of localized corrosion in Al-Cu-Li alloy

The mechanism of localized corrosion in 2A97 aluminium alloy has been investigated. Electron backscatter diffraction analysis was performed at the localized corrosion site to determine the grain-stored energy. The relationship between the grain-stored energy, namely the population density of crystallographic defects, and the corrosion susceptibility of the alloy has been established. It was revealed that the grain boundaries that surrounded grains of relatively high stored energy were preferentially attacked. Intergranular corrosion could occur at grain boundaries where second phase precipitate was absent. Non-uniform attack of the adjacent grain interior was also observed along the attacked grain boundary, with preferential dissolution of the grains with high stored energy. Copyright (C) 2015 The Authors Surface and Interface Analysis Published by John Wiley & Sons Ltd.