THE CATHODIC REACTION DURING REPASSIVATION OF ALUMINUM IN OPEN-CIRCUIT

Experiments have been carried out to investigate the role of cathodic processes in the repassivation of aluminium in open circuit using the guillotined electrode. These measurements involve application of an electrochemical perturbation to the open-circuit potential. The results reveal that the rate of the cathodic reaction at constant potential is independent of the film thickness, but the open-circuit repassivation potential transient depends on the cathodic reactant. The rate-control of these processes cannot be explained by electron tunnelling alone.