Application of electrochemical noise analysis to corroding aluminium alloys

On practical aluminium alloys, due to the complex interactions between microstructural features and local pH variations, corrosion initiation is generally observed close to intermetallics, and corrosion propagation requires the presence of a cluster of intermetallics immediately beneath the surface. Electrochemical investigations directed to the characterization of the corrosion process should be performed with minimal perturbation, in order to obtain information that can be translated into real-life performance. Uniquely, electrochemical noise measurements enable information to be gathered by exploiting the natural fluctuations in the electrochemical potential and current flowing between two or more galvanically coupled corroding electrodes. In this work, the corrosion behaviour of AA2024T3 aluminium alloy and high-purity aluminium macroscopic electrodes immersed in 3.5% NaCl at different pH was examined. The findings show that time-resolved electrochemical noise analysis is a powerful tool for understanding the details of the corrosion process on aluminium alloys. Copyright ?? 2012 John Wiley & Sons, Ltd. Copyright ?? 2012 John Wiley & Sons, Ltd.