In-situ Observation of Aluminum Alloy during Corrosion Using Open-Loop Electric Potential Microscopy and Comparison with the Potential Distribution in Atmosphere

Abstract

Open-Loop Electric Potential Microscopy （OL-EPM） is the evaluation method that enables measurement of potential distribution on the metal surface in liquid, but the relationship between the surface potentials in liquid and atmosphere is not clear. Therefore, we attempted to compare the potential distribution in atmosphere using Kelvin probe Force Microscopy （KFM） to the potential in liquid using OL-EPM at the same position on the aluminum alloy. As a result of the observation, the potential distribution obtained with OL-EPM in deionized water showed similar results to KFM. On the other hand, in corrosive environments the potential distribution showed local corrosion cell, which revealed that the potential distribution obtained with OL-EPM is different from that with KFM.