Corrosion chemical mechanism in aggressive liquid of MAO coatings based on OT-4 titanium alloys

Abstract

Microarc oxidation of alloys is widely used to obtain multifunctional coatings with unique properties. One of the topical issues in the application of the microarc oxidation is to increase the corrosion resistance of titanium alloys. In this article, the corrosion resistance of various microarc oxidation coatings of a titanium alloy in chemically aggressive liquids is determined. Comparative analysis of microarc oxidation coatings chemical resistance of the titanium alloy OT-4 showed a high coating resistance to the corrosive liquid exposure. The highest corrosion coefficient was determined when the alloy was exposed to concentrated sulphuric and hydrochloric acids. Virtually no corrosion of microarc oxidation coatings was observed in dilute acids (H2SO4 and HCl) and NaOH alkali solution.