Corrosion protection of 2024-T3 aluminium alloy by electro-polymerized 3-amino 1,2,4-triazole in sulphate solution containing chloride

Electro-oxidation of 3-amino 1,2,4-triazole (ATA) on Al 2024-T3 alloy carried out simultaneously to the anodizing process in methanol acetate or in aqueous sulphate medium, leads to the formation of CuI–ATA complex upon Cu-rich particles. The anodizing film grows, in both media, according to high field-assisted migration mechanism and the potential field is in the order of 106 V cm−1. Significant protective effect of films towards localized corrosion was observed due to CuI–ATA and poly(ATA) formations on Cu-rich particles. These complex layers hinder also the oxygen reduction reaction leading to a lower corrosion rate at the open circuit conditions.

Research highlights► Corrosion protection of Al 2024 with electro-polymerized film upon Cu-rich particles. ► CuI–poly(ATA) complex forms upon Cu-rich particles during anodization of Al 2024. ► Electro-polymerization in methanol medium yields highly protective layer. ► Significant protection towards localized corrosion is obtained.