FRACTAL CHARACTERIZATION OF 2-DIMENSIONAL ALUMINUM CORROSION FRONTS

The corrosion of aluminum foils in a two-dimensional cell has been inv estigated experimentally. The corrosion was allowed to attack from onl y one side of an otherwise encapsulated metal foil. A IM NaCl (pH = 12 ) electrolyte was used and the experiments were controlled potentiosta tically. Experiments were performed at two different potentials. Photo graphs from the experiments were digitized and the interfaces between the electrolyte and metal (the corrosion fronts) were identified. The corrosion fronts were analyzed using four different methods, which sho wed that the fronts can be described in terms of self-affine fractal g eometry over a significant range of length scales. The width as a func tion of length showed self-affine scaling with a Hurst exponent of 0.6 5 +/- 0.05 for both fronts. Results from corrosion experiments using z inc and copper are briefly mentioned.