Growth of corrosion-resistant manganese oxide coatings on an aluminum alloy

Data are presented on the nucleation and growth of corrosion-resistant manganese-oxide-based films on the surface of aluminum alloy 2024 in an alkaline KMnO4 solution at room temperature and elevated temperatures, which accelerate film growth. We consider the morphological evolution of the films and secondphase particles present on the alloy surface, which impair the corrosion resistance of the alloy. Also addressed are the feasibility of MnO4- incorporation into the growing film and the associated ability of the coating to selfheal when slightly damaged. Such coatings are a viable alternative to chromate-based coatings, which are currently in wide use.