Influence of pH on Performance of SiO2 Film Prepared by Sol-Gel

An anti-corrosion silicon dioxide coating on the surface of AZ91D was prepared by sol-gel method. Characteristics and the surface morphology of the SiO2 sol coatings were tested and analyzed. The results showed that an uniform, repeatable SiO2 sol-gel coating was obtained when the mass ratio of TEOS ∶ ethanol ∶ water was 1∶15∶9.5, soaking time was 120 s, dipped for once, drying temperature was 120 ℃, pH of SiO2 sol was 2.8. The coating had fairly good corrosion resistance and thus improved the corrosion resistance of the AZ91D alloy greatly.