A one-dimensional time-dependent model for studying oxide film growth on metallic surfaces

Corrosion resistance of industrial metals and alloys is largely imparted by the formation of a stable oxide film on the surface that kinetically limits the process of corrosion. Developing a fundamental knowledge of the processes involved in the oxide layer formation and growth is thus important for designing corrosion-resistant alloys. In this work, a model for oxide growth tracking two species (the oxygen and metal vacancies) was presented. The model accounted for species transport and interfacial chemistry. The potential profile was obtained by solving the Poisson equation without needing to invoke the typical linear assumption. Moreover, the fully time-dependent concentration and potential profiles were obtained and the oxide thickness was allowed to evolve by allowing the movement of the domain boundaries at either end. The results were analyzed and the effects of different parameters on the model were discussed.