Preparation and Corrosion Performance of a Doping Modified Hybrid Film on Aluminum Tube

Abstract

A hybrid sol was prepared by sol-gel technique with precursors of ethylsilicate(TEOS)and vinyltriethoxysilane(KH151), and which then was further doped with 1.5×10-3mol/L Ce(NO3)3to get a Ce-doped hybrid sol. A coating of this Ce-doped hybrid sol was prepared on aluminum tube by dipping method. Results of bluestone drips test, neutral salt spray test and electrochemical measurement showed that the coating doping modified hybrid film possessed superior corrosion performance rather than the conventional chromate passivation film. The infrared spectrum of the coating revealed that there existed different types of Si—O—Si covalent bonds and organic functional groups C=C covalent bonds, which might enhance the hydrophobicity of the coating. Finally SEM examination showed that the formed coating was dense, uniform and smooth.