Enhancing Pitting Corrosion Resistance of Aluminium by Anodizing Process

Abstract

In present study, the anodizing of aluminium was carried out in sulphuric acid/tartaric acid electrolyte system to increase pitting corrosion resistance. The corrosion resistance of the oxide coating of aluminium was determined by potentiodynamic polarization test. The surface morphology was investigated using scanning electron microscope before and after the corrosion test. It was found that anodic oxide coating obtained in sulphuric acid/tartaric acid showed higher pitting corrosion resistance.

Microstructure and corrosion performance of Al0.5FeCoNiCrMn coating prepared by plasma spraying mechanically alloyed powders

“…The electrode potential of the metal oxide phase was higher than those of the FCC and BCC phases. Therefore, metal oxides are used as cathodes in micro-batteries [40]. Because the content of metal oxides in the coating was much lower than the contents of the FCC and BCC phases, ‘large anode – small cathode’ micro-battery corrosion occurred, which significantly reduced and the corrosion rate of the anode [41].…”