Microstructure and Properties of Plasma Electrolytic Oxidation Composite Coating Modified by Mesoporous SiO2 on Magnesium Alloy Surface
For a composite coating with a self-repairing capability on the surface of magnesium alloys to be prepared,mesoporous SiO2 microcontainers loaded with 8-hydroxyquinoline(8-HQ)were doped into the epoxy resin coating and then the mixture was coated on the surface of magnesium alloy AZ91D which had been treated by plasma electrolytic oxidation.The loading and release of 8-HQ in microcontainers were studied by TEM,FT-IR,UV and TGA.The surface morphology,corrosion resistance,self-repairing capability and mechanism of the modified composite coating were studied by SEM and the electrochemical test.The research results are as follows.The maximum loading of 8-HQ in mesoporous SiO2 is approximately 16％,and 8-HQ is released completely within 40 min.The self-repairing capability of the coating was demonstrated by pre-defects,with a self-repairing efficiency of about 93％.The modified composite coating exhibits better corrosion resistance,which will extend the service life of magnesium alloys in practical applications.
metal surface protection technologyAZ91D magnesium alloycorrosion inhibitormesoporous SiO2
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