Review on the Application of Additives in Micro-arc Oxidation of Titanium Alloy

Abstract

Micro-arc oxidation technology of titanium alloy is an efficient, economical and environmentally friendly surface treatment method to improve the properties of titanium alloy. Various additives have been widely used in the industry to improve the properties of micro-arc oxidation film. However, in the process of micro-arc oxidation, due to spark discharge, gas evolution, rapid cooling of molten substances and other factors, a large number of micropores and micro-cracks will be generated in the film. These defects will form a loose layer with poor bonding force on the film surface, which will easily peel off under external force and cause serious abrasive wear on the film surface, which will lead to the failure of the film. A large number of studies show that adding additives into electrolyte can achieve the effect of filling micropores and microcracks, thus improving the corrosion resistance and wear resistance of micro-arc oxidation film. The film obtained by adding additives to the micro-arc oxidation electrolyte not only has excellent metallurgical bonding force, but also can significantly improve the hardness, wear resistance and corrosion resistance of its surface. In this paper, the research status of various additives in micro-arc oxidation of titanium alloy is introduced from three categories: soluble salt additives, nano-particle additives and organic additives, and their action mechanisms are discussed.