Nanostructured titania-alumina coatings containing 1.2%, 3.6%, and 4.8% Benzotriazole as the self-healing agent are deposited on Al 2024 by the sol-gel method and dip coating. The phase composition and surface morphology are evaluated by XRD, FE-SEM, and AFM and the corrosion behavior is examined by electrochemical impedance spectroscopy and polarization tests in 3.5% NaCl solution for different immersion time periods of 1, 48, and 96 h. Uniform, homogeneous, and crack-free coatings with a thickness of about 3 μm are obtained. Release of Benzotriazole from the coatings blocks active sites and produces a barrier layer to improve the corrosion resistance of Al 2024. A protection efficiency of 76% is observed from the titania-alumina coating with 3.6% Benzotriazole and investigation of the impedance with immersion time confirms the self-healing behavior.
