Farzad Mohammadi

Corrosion Behavior of 2024 Aluminum Alloy Anodized in Sulfuric Acid Containing Inorganic Inhibitor

The effects of potassium permanganate, as a corrosion inhibitor, in different concentration on morphology, composition and thickness as well as corrosion resistance of anodic film formed on 2024-T3 aluminum alloy in sulfuric acid were investigated in this paper. Surface morphology and chemical composition of oxide film were studied using field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectroscopy (EDX). Potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS) were conducted to assess the corrosion performance of the coatings. The results showed that presence of potassium permanganate during anodizing process results in more compact and thicker anodic film with smaller pore size. Effects of potassium permanganate increased with concentration. Using permanganate ions improved corrosion resistance of the formed anodic layer, which is about 45% and 94% inhibition for 0.01 and 0.1M permanganate, respectively.