Influence of Organic Additives on Performance of Aluminum Anodic Oxide Films

Aluminum anodic oxide (AAO) films were fabricated in sulfuric acid-based solution containing different organic additives,and the thickness,hardness and corrosion resistance of AAO films were measured respectively.Electrochemical impedance spectroscopy (EIS) technique was used to analyze the corrosion resistance mechanism of AAO films.The results indicated that adding organic additives could improve the thickness,hardness and corrosion resistance of AAO films,and sulfuric acid + cerium salt + citric acid system was the best additive.The corrosion resistance of AAO films were improved greatly because the stable macromolecular complex ions formed by the synergistic effect of cerium salt and citric acid,which could impede the entering of aggresive ions.