Corrosion Performance Of Epoxy Coating Containing Y Zeolites On Mg Alloy

In this paper,the HY and CeY zeolites were modified by using ?-(2,3-epoxy propyl)proplyl trimethyl(KH-560)and tridecafluorooctyl triethoxy silane(FSi-13).The epoxy coating containing the silane modified Y zeolites were prepared by the bar coating on the magnesium alloy surface.Besides,the morphology of zeolites,the morphology and thickness of the coating were analyzed by FT-IR,XRD and SEM.Meanwhile anti-corrosive performance of the coating is mainly measured by electrochemical impedance spectroscopy(EIS)in various days.The HY zeolites were sythesised by ion exchanged method.The 0.2% HY,0.5% HY and 1.0% HY zeolites were added to the epoxy coating,respectively.The epoxy coatings were coated on the magnesium alloy surface.The SEM results show that HY zeolites are uniformly distributed in the epoxy coating is relativelt smooth.The thickness of the coating was 34±5 ?m.The corrosion properties of the samples immersed in 3.5%NaCl solution were measured by means of EIS.The results show that the epoxy coating with the coating containing 0.5% HY zeolites has the better corrosion resistance.Its corrosion photos in various days are coherent with the EIS results.Finally,the mechanism the zeolites enhanced the corrosion resistance of the coating was also prorosed.The HY zeolites were modified by KH-560 and FSi-13,respectively.The epoxy containing modified KH-560 and FSi-13 are coated on the surface of magnesium alloy.The EIS results show that the corrosion resistance of the epoxy coating with the silane modified HY zeolites was better than that of the unmodified coating.FSi-13 contains a large number of hydrophobic groups(C-F bond),the epoxy coating containing the FSi-13 modified Y zeolites still has higher low-frequency impedance modulus after 58 days,better barrier properties and effective long-term protection for the magnesium.The CeY zeolites were prepared by ion exchanged method,and FSi-13 modified CeY zeolites.The epoxy coatings containing CeY zeolites and or FSi-13 modified CeY zeolites were coated on the surface of magnesium alloys.Their results show that their low-frequency of impedance modulus gradually decrease and then increase with increase of time,and finally slightly drop at the end of the immersion.The results show that the coating has self-healing porperties.These above-mentioned coatings can effivtively inhibit the corrosion of the Mg alloy.Optical photographs of the samles immersed in 3.5% NaCl solution at different immersion times show that the epoxy coating with the FSi-13 modified CeY zeolites has no obvious corrosion on the surface after 60 days of immersion test.These results show that the epoxy coating containing CeY zeolites,especially FSi-13 modified CeY zeolites,can improve the corrosion resistance of the epoxy coating.The mechanism of the anticorrosion was also proposed.