A technique for studying the 3-dimensional shape of corrosion pits

A technique has been developed for studying the 3-dimensional shapes of corrosion pits. The technique involved the preparation of epoxy replicas of pits and has been demonstrated in preliminary studies of pitting corrosion in a 2024-T3 aluminum alloys. The replicas are shown to be faithful reproductions of the corroded surface, reflecting all of the key features of small and large corrosion pits. They provide a 3-dimensional perspective that is heretofore missing from surface observations and serial sectioning techniques, and can aid in the quantitative assessments of the kinetics and the mechanistic understanding of pitting corrosion. Measurement techniques are being developed to capture the key geometric information from the replicas. Further studies of the mechanism and kinetics of pitting corrosion in the high-strength aluminum alloys using these techniques are in progress, and will be reported.