Construction of anodizing/ silane / graphene oxide composite film and its corrosion resistance mechanism on aluminum alloy surface

In order to improve the corrosion resistance of aluminum alloy, anodic oxide/perfluorooctyltriethoxysilane/ graphene oxide (AAO/POTS/GO) composite film was designed through molecular dynamics simulation and quantum chemical calculation, and the composite film was prepared by anodizing and self-assembly technology. The morphology, composition and structure of the film were characterized by SEM, EDS, Raman, XRD and XPS, and the corrosion resistance was characterized by electrochemical test and salt spray test. The impedance of the AAO/POTS/GO composite film is 4 orders of magnitude higher than that of the AAO film, reaching 5.17 x 10(9) Omega.cm(2). The corrosion current density is 3 orders of magnitude lower than that of AAO film. The corrosion resistance efficiency reaches 99.98%, and the corrosion rate is 5.494 x 10 (-5) mm/year, and the salt spray test does not appear until the 40th day. Theoretical simulation shows that the chemical bond of Si-O-Al is formed by the interaction between the hydrolyzed Si-O-C2H5 and the metal surface atoms. This result is consistent with the final result of the experiment in this paper.