Effect of silica sol on boric-sulfuric acid anodic oxidation of LY12CZ aluminum alloy

Aluminum alloy anodizing coatings were prepared for LY12CZ in the boric-sulfuric acid solution (45g/L sulfuric acid, 8g/L boric acid) with the addition of 10%, 20%, 30% (volume fraction)silica sol, with the gradient voltage of 15V. The current and voltage transients of the anodizing process were collected by data collection instrument. The surface morphologies, microstructure and chemical composition of the anodic coatings were characterized by scanning electron microscopy (SEM). The corrosion resistance was examined by neutral salt spray, electrochemical impedance spectroscopy (EIS) test and titrating test. The results show that the different concentration of silica sol addition can influence the forming and dissolution of anodizing coatings, improve the compactness smoothness and corrosion resistance during the anodizing process in the boric-sulfuric acid solution. © 2016, Journal of Materials Engineering. All right reserved.