Electrochemical characterization of anti-corrosion coatings formed on 6061 aluminum alloy by plasma electrolytic oxidation in the corrosion inhibitor-enriched aqueous solutions

The 6061 aluminum alloy was surface-treated by plasma electrolytic oxidation (PEO) in silicate-and borate based electrolyte systems. The authors attempted to incorporate selected corrosion inhibitors (8-hydroxyquinoline, 2-mercaptobenzothiazole, poly(acrylic acid) with molecular weights of 1800 and 450,000 g mol(-1), and acrylic acid) into the oxide coating to provide long-lasting protection of the substrate. These inhibitors were either added directly to the electrolyte for the treatment or loaded into the coatings through a sequential PEO procedure. Electrochemical corrosion tests showed that acrylic acid-modified coatings provided the best protection. In general, of the two methods, the sequential PEO gave more reproducible anti-corrosion effects.

Automated summary

In this study, the 6061 aluminum alloy was surface-treated using plasma electrolytic oxidation (PEO) to provide long-lasting corrosion protection. Selected corrosion inhibitors were incorporated into the oxide coating either by adding them directly to the electrolyte or through a sequential PEO process. The results showed that acrylic acid-modified coatings provided the best protection, and the sequential PEO method had more reproducible anti-corrosion effects.