Controlled oxide film formation to improve the corrosion resistance of aluminum alloy

摘要

The aluminum and its alloys have received considerable attention for transport industry, aerospace in special, because of their low density and good mechanical properties. Even if the aluminum is covered by a thin native oxide film it can present voids and cracks. Various methods are used for aluminum alloy surface treatment. Anodic oxidation is the most used. In this research work an anodic oxide film was prepared by controlled anodic oxidation at different voltages on 1050 aluminum alloy surface. The effect of anodized layer on the corrosion behavior of aluminum alloy 1050 was investigated by electrochemical methods such as open circuit potential electrochemical impedance spectroscopy and cyclic voltammetry. The results were compared with those obtained for untreated aluminum alloy. It was found that the surface treatment form a controlled oxide film which improves the corrosion performance of 1050 aluminum alloy. The results are supported by optical microscopy micrographs taken before and after oxidation and after corrosion tests.