Development and characterization of hydrophobic anodized aluminum layer to act as a long-lasting protective film in corrosion

This work focuses on the development of a novel hydrophobic process for anodized aluminum AA2024-T3 which consists of a combination of corrosion inhibitors: sodium metavanadate with a gamma-irradiated fluoropolymer. The anodizing films, formed in sulfuric acid media, were sealed by using different aqueous solutions such as boiling water, potassium dichromate, and cerium nitrate. The corrosion resistance results obtained by electrochemical impedance spectroscopy (EIS) showed that samples sealed with Ce(NO3)(3) had a higher average value of total impedance of 10(11) Omega cm(2) obtained at low frequencies in 0.1 M NaCl solution. Water contact angle measurements revealed best results at 128.8 degrees. X-ray photoelectron microscopy in conjunction with scanning electron microscopy indicated the formation of a layer of fluoro compound above the anodized aluminum. X-ray diffraction, infrared spectroscopy, and differential scanning calorimetry demonstrated thermal modifications of the gamma-irradiated fluoropolymer.