Corrosion Behaviour of High-Energy Ball Milled Nanocrystalline Al Alloys

Aluminum exhibits excellent corrosion resistance in the pH range of 4–8 due to the presence of a thin “passive film” upon the metal surface [1–9]. Breakdown of the passive film caused by several metallurgical (defects, impurities, secondary phases etc.) and environmental (halide ions, high or low pH, temperature) factors leads to the significant localized corrosion [9–17]. The corrosion of Al is escalated by the presence of intermetallics, which are formed due to the alloying additions and impurities as most of the elements possess limited solid solubility in Al and therefore intermetallics form during production, processing, and service conditions [18–22].