Review of micro-arc oxidation of titanium alloys: Mechanism, properties and applications

Titanium (Ti) and its alloys have great application potential. However, their relatively poor surface hardness, wear resistance, corrosion resistance, and biological activity greatly limit their effectiveness in practical applications. As a surface treatment method, the micro-arc oxidation (MAO) process has attracted much attention because it does not require expensive production equipment and is simple to operate. This paper discussed and summarized the mechanism of micro-arc oxidation and some classic models, which require development to provide better understanding and guidance for future research. Subsequently, the influencing factors of the formation of the micro-arc oxidation coating during micro-arc oxidation process were analyzed in detail. In addition, common applications of micro-arc oxidation coatings, including biomedical applications, wear resistance, corrosion resistance properties, and decoration, were summarized independently. Finally, existing problems and future prospects of the titanium alloy micro-arc oxidation process were discussed to facilitate the wide application of titanium alloy MAO process.