Investigation Corrosion Behavior of Nanostructured Hybrid Coating Applied by Sol- Gel Method on Al 2024

Nanostructured titanium oxide coating due to the optical properties, resistance to oxidation, corrosion, and erosion has become highly regarded. There are different ways for applying nanostructure coating such as CVD, PVD, sol - gel and so on. Among of these methods, the sol - gel method was used more application, due to the ease of having such benefits as efficiency, homogeneity and uniformity of the chemical composition of the coating. So, in this paper, the intermediate coating, adhesive and porous nanostructured titanium oxide, as maintenance reserves cerium inhibitor, applied by sol - gel method on aluminum 2024, after that a layer of homogeneous, uniform and compact titanium oxide applied on the middle layer, then the structural properties, morphology and coating composition were investigated by XRD, FESEM and AFM and corrosion properties of the coatings in 3, 5% NaCl solution was measured by electrochemical techniques such as polarization and impedance measured. The results showed homogeneity, uniformity and free crack coating and also improving the corrosion resistance of Al 2024 from 36 to 2449 (KΩcm2), about 68 times. These effects can be due to self-healing mechanism of nano cerium inhibitors by releasing and producing cerium hydroxide and finally prevent cracks propagation.