The reliability of metastable pit sizes estimated from dissolution current in aluminium alloys

By treating each current transient as a signal arising from single discrete pit events, the pit sizes of the locations associated with recurring and co-occurring pit events could be underestimated or overestimated. In the present study, the error introduced in the estimated pit sizes by this hypothesis and other factors such as the hydrogen evolution occurring within pits and pit geometry were investigated in-situ by mapping the pit locations. Further, with the insights derived, a criterion was proposed to identify the transients associated with recursive pit events that eventually developed into stable pits.