The electrochemistry of intermetallic particles and localized corrosion in Al alloys

Intermetallic particle electrochemistry plays significant role in localized corrosion and stress-corrosion cracking of aluminum alloys. This article presents specific examples from recent and on-going studies of stress-corrosion cracking in Al-Mg alloys and localized corrosion in Al-Cu alloys. The common approach in these examples is an explicit accounting of the intermetallic particle-dissolution characteristics, which is developed by measuring the electrochemical behavior of bulk analog compounds. Findings from these types of measurements combined with results from new and advanced small-length scale measurements confirm some of the established ideas about localized corrosion in aluminum alloys, but also lead to new insights that are important for a thorough understanding of corrosion damage accumulation.