Improving the Corrosion Behaviour of 6061 Aluminum Alloy by Controlled Anodic Formed Oxide Layer

Abstract

This research work investigates the influence of anodic oxide film obtained in sulphuric electrolyte on the corrosion behavior of 6061 aluminum alloy in natural sea water. Corrosion behavior of untreated and anodized 6061 aluminum alloy was studied using electrochemical methods such as: open circuit potential and electrochemical impedance spectroscopy. All the tests were performed in an aerate sea water with pH=7.63 at room temperature (25oC). The electrochemical results are in good agreement with optical microscopy images. The polarization resistance of aluminum oxide film increases as compared with the untreated aluminum alloy this showing an improving of corrosion resistance after anodic oxidation. These results demonstrate the advantages of the as-fabricated anodic oxide layer as a barrier thin film to marine corrosion.