To meet the development of light alloy technology, more and more aluminum alloy materials have been used on the ships and armored equipments. However, the corrosion problem is very serious. Data shows that nearly half of the maintenance cost of aluminum ships is used to repair corrosion damage in our country. The micro-arc oxidation(MAO) of aluminum alloy is a surface treatment technology which originated in the late last century. By generating ceramic layer on the surface, aluminum alloy gets a better anti-corrosion effect. This technology has special advantages when dealing with complex parts and components. The MAO coatings composed mainly of α-Al2O3 and γ-Al2O3 on the surface of aluminum alloy, which has high hardness, corrosion resistance and wear resistance. But due to the effect of high pressure breakdown, the aluminum alloy surface formed many discharge channel, causing a large number of holes in the film. In order to improve its corrosion protection effect, scholars have done a lot of research. The factors affecting corrosion resistance can be summarized into four aspects: electrolyte, electrical parameters, oxidation time and additives. Generally speaking, electrolytes and additives have a direct effect on the composition of MAO coatings. Appropriate additives can improve the porosity of film, especially the nanoparticles additives can improve the hardness and strength through the second phase dispersion strengthening mechanism. In addition, the electrical parameters and oxidation time have influences on the film forming efficiency, film thickness and phase structure. The corrosion resis-tance and comprehensive properties of MAO coatings are influenced by the interaction of all the factors. Developed countries represented by the United States have begun to use aluminum alloy micro-arc oxidation technology in industry since the 1970s. Russia's theoretical research is relatively in-depth and is in a leading position in the world. However, micro-arc oxidation is completed instantly and involves chemistry, electrochemistry, plasma and other reactions. The mechanism is very complicated and there is still no unified mo-del can explain perfectly. Research in our country began in the 1990s, and some achievements have been made in theoretical accumulation and engineering application, especially in some small aluminum alloy workpieces. In order to provide a reference for further research, this paper summarizes the corrosion protection mechanism of MAO coatings, combs and discusses the factors affecting it's corrosion resistance, and prospects the development of this technology. © 2021, Materials Review Magazine. All right reserved.
