In order to improve the corrosion resistance of 6A16 aluminum alloy and realize the accurate regulation of micro-structure and composition of micro-arc oxidation coating, the TiC/MAO composite coating was prepared on the surface of 6A16 aluminum alloy by micro-arc oxidation technology and hydrothermal treatment, and the preparation parameters were optimized by experimental test method. Results showed that the optimal parameters for the preparation of composite coating by hydrothermal method were as follows: the pH value of the solution was 8, the reaction time was 24 h, and the reaction temperature was 180 ℃. When pH value of solution was 8, a dense TiC film was formed, and the sample had the minimum corrosion current and the maximum corrosion potential, showing excellent corrosion resistance. When the reaction time increased to 24 h, more hydrotalcite was formed on the surface of the sample in a granular shape, not a flake structure. At this time, a smaller corrosion current was obtained and the corrosion potential was further increased, indicating better corrosion resistance. When the reaction temperature raised to 180 ℃, more TiC was generated on the sample surface, which resulted in the formation of a dense TiC structure, obvious laminar appearance characteristics, and a decrease in the number of micropores. At this time, excellent passivation performance was obtained, and the corrosion current was also low.
