Silica sol sealing process and properties of micro-arc oxidation film on 7075 aluminum alloy

doi:10.13251/j.issn.0254-6051.2021.05.039

Abstract

Abstract: Silica sol sealing process was carried out for the micro-arc oxidation film on 7075 aluminum alloy. The microscopic surface morphology, cross-sectional morphology, phase composition, wear resistance and corrosion resistance of the micro-arc oxide film before and after the silica sol sealing were analyzed by scanning electron microscope, X-ray diffractometer, high temperature friction and wear test machine and electrochemical workstation. And the influence of different silica sol-gel sealing processes on the sealing effect was investigated. The results show that compared with the unsealed micro-arc oxidation film, the micro-holes in the micro-arc oxidation film after sealing are obviously reduced, the roughness of the film is reduced, and the wear resistance is improved. The corrosion potential of the micro-arc oxidation film after sealing is positively shifted from -0.62 V(vs SCE) to -0.36 V(vs SCE), the corrosion current density drops from 2.44×10^-3 A·cm^-2 to 2.03×10^-4 A·cm^-2, and the corrosion resistance of the micro-arc oxidation film is significantly improved after sealing. However, the corrosion resistance of the micro-arc oxidation film sealed by the dipping and pulling method is better than that sealed by the spin coating method.

Key words: micro-arc oxidation film, sealing, silica sol, dipping and pulling method, spin coating method

CLC Number:

TG174

Li Jun, Jiang Bo, Wang Chao, Song Renguo. Silica sol sealing process and properties of micro-arc oxidation film on 7075 aluminum alloy[J]. Heat Treatment of Metals, 2021, 46(5): 224-228.

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