Plasma Electrolytic Oxidation Coatings on Aluminum Alloys: Microstructures, Properties, and Applications

This work is licensed under Creative Commons Attribution 4.0 License MCMS.MS.ID.000526. Abstract Aluminum (Al) and its alloys are widely used in many industries, and anodic oxidation (AO) and plasma electrolytic oxidation (PEO) are two of the most important technical routes to improve their corrosion resistance and mechanical properties. This review paper covers both AO and PEO of Al alloys, in order to facilitate a comparison between the two technologies. A general overview of AO and PEO is provided. Then the focus is on PEO coatings, including the microstructure of PEO coatings, the effect of various PEO process parameters on the microstructure and properties of the coating. An attention is paid to the corrosion resistance and mechanical properties of PEO coatings on aluminum and its alloys. Finally, the applications of PEO coatings on Al alloys are summarized. The review intends to give a balanced coverage on recent development on PEO process and coatings, and to stimulate more research and industry interests in PEO coatings.