The corrosion behavior of titania-alumina-Benzotriazole and functionally graded (FG) coatings deposited on AA 2024-T3 is investigated. The FG coatings are doped with different amounts of Benzotriazole (BTA) as an inhibitor and the Al2O3–TiO2-BTA coating has a similar amount of BTA in the layers. The coatings are deposited by the sol-gel and dip-coating techniques and the morphology, structure, and corrosion resistance are investigated systematically. The amorphous TiO2–Al2O3-BTA and FG coatings with thicknesses of 2.3 and 2.6 μm show corrosion resistance of 105,672 Ω Cm2 and 252,731Ω. Cm2, respectively, after immersion in 3.5% NaCl for 96 h. The difference is caused by controllable release of BTA from the FG coatings. The results show that the FG coatings are superior to conventional nanostructured TiO2–Al2O3-BTA coatings from the perspective of corrosion protection.
