Growth behavior of anodic oxide formed by aluminum anodizing in glutaric and its derivative acid electrolytes

• Published in: Applied surface science Vol. 321; pp. 364 - 370
• Main Authors: Nakajima, Daiki, Kikuchi, Tatsuya, Natsui, Shungo, Suzuki, Ryosuke O.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.12.2014; Elsevier
• Subjects: Acetonedicarboxylic acid; Aluminum; Aluminum base alloys; Aluminum oxide; Anodic; Anodizing; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Constants; Cross-disciplinary physics: materials science; rheology; Derivatives; Exact sciences and technology; Glutaric acid; Ketoglutaric acid; Oxides; Physics; Pitting (corrosion); Acetonedicarboxylic acid; Ketoglutaric acid; Aluminum; Anodizing; Glutaric acid; Aluminium
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2014.10.014

•A thin barrier anodic oxide is formed by glutaric acid anodizing.•A thick anodic porous alumina is formed by ketoglutaric acid anodizing.•An anodic porous alumina is also formed by acetonedicarboxylic acid anodizing.•Acid dissociation constants are an important factor for anodic porous alumina. The growth behavior of anodic oxide films formed via anodizing in glutaric and its derivative acid solutions was investigated based on the acid dissociation constants of electrolytes. High-purity aluminum foils were anodized in glutaric, ketoglutaric, and acetonedicarboxylic acid solutions under various electrochemical conditions. A thin barrier anodic oxide film grew uniformly on the aluminum substrate by glutaric acid anodizing, and further anodizing caused the film to breakdown due to a high electric field. In contrast, an anodic porous alumina film with a submicrometer-scale cell diameter was successfully formed by ketoglutaric acid anodizing at 293K. However, the increase and decrease in the temperature of the ketoglutaric acid resulted in non-uniform oxide growth and localized pitting corrosion of the aluminum substrate. An anodic porous alumina film could also be fabricated by acetonedicarboxylic acid anodizing due to the relatively low dissociation constants associated with the acid. Acid dissociation constants are an important factor for the fabrication of anodic porous alumina films.