Research progress on effects of additives and pre- and post-treatment processes on corrosion resistance of micro-arc oxidation coatings on titanium and its alloys

Titanium and its alloys are widely used in various fields owing to their exceptional wear resistance, heat resistance and biocompatibility. However, they still exhibit shortcomings, such as insufficient corrosion resistance, when used in specific working environments. micro-arc oxidation (MAO) has gained considerable attention in recent years for the preparation of ceramic coatings with good bonding force, wear resistance, corrosion resistance, and biological activity on aluminum, magnesium, titanium, and their alloys. Because of the porous structure of MAO coatings, researchers often enhance the corrosion resistance of MAO coatings on titanium and its alloys by incorporating different types of additives or using pre- and post-treatment processes. This paper reviews the mechanism of MAO technology and the effects of various types of additives and pre- and post-treatment processes on the corrosion resistance of MAO coatings on titanium and its alloys based on recent literature and predicts future development trends.