Localized Corrosion of Aluminum Alloys—A Review

Localized corrosion, which usually appears as pitting, crevice corrosion (CC), or certain aspects of stress corrosion cracking (SCC), is a multi-step process. This review is organized by a consideration of the four steps involved in localized corrosion: (1) adsorption of the reactive anion on the oxide covered aluminum; (2) chemical reaction of the adsorbed anion with the aluminum ion in the aluminum oxide lattice or the precipitated aluminum hydroxide; (3) thinning of the oxide by dissolution; and (4) direct attack of the exposed metal by the anion, perhaps assisted by an anodic potential. The experimental work reported in the literature is evaluated within this framework.