The role of acid–base interactions in the pitting corrosion of aluminum: a review

Abstract

Abstract The review describes an electrode kinetic model of aluminum pitting nucleation taking into account the charge of the metal surface, the adsorption of chloride ions on the oxide surface, their penetration through the oxide film with the help of oxygen vacancies, and the dissolution of the underlying substrate with the initiation of pitting corrosion at the metal/oxide interface. It is shown that the critical pitting potential is a function of the potential of a thin layer of aluminum surface covered by oxide and the value of the pitting potential of a binary surface alloying is related to the isoelectric point of the alloying element oxide in the binary alloy. An electrode kinetic model of pitting initiation is described, which was used to explain the effect of surface alloying on the pitting initiation on binary alloys. A method for changing the surface charge by forming foreign surface organosilicon nanolayers bearing both negatively and positively charged groups was proposed. It has been established that four characteristics (q, Ψ1-potential, Epit and the tendency of aluminum to depassivate) depend on the nature of ion-exchange groups, the degree of their acid dissociation, and the ion-chemical interaction with activator ions.