Characterization of the atmospheric corrosion of aluminum in archipelagic subtropical environments

Abstract

The atmospheric corrosion of aluminum in archipelagic subtropical environments has been investigated in Tenerife (Canary Islands, Spain). Pitting corrosion has been characterized in terms of the density and depth of the pits. Though longer exposures originate greater pit densities on aluminum, pit size is greatly influenced by the concentration of pollutants and the wetness of the atmospheres. A direct linear relationship between the pitting parameters and the chloride content in the environment was found. The effect of SO2 is less significant, though electrochemical tests indicate that the addition of sulphate ions to chloride-containing solutions favours the growth of bigger pits.