| Magnesium alloy micro-arc oxidation ceramic coating has high wear resistance and excellent performance.However,the surface insulation properties of the magnesium alloy micro-arc oxidation ceramic coating lead to the accumulation of static electricity in the device casing when it is applied to many radio equipment casings,thereby affecting the working life of the device.The organic conductive coating is a coating with excellent electrical conductivity and corrosion resistance formed by the combination of the conductive filler and the high polymer,so that the organic conductive coating is prepared on the surface of the magnesium alloy micro-arc oxidation ceramic coating,and the coating surface can be realized not only conductivity can further improve its corrosion resistance by means of high polymers.In this paper,copper powder was used as conductive filler,and it was added into epoxy resin.The organic conductive coating was prepared on the surface of A231B magnesium alloy micro-arc oxidation ceramic coating by blending method.Determining the effect of the micro-arc oxidation ceramic coating on the bonding strength between the organic conductive coating and the substrate.The effects of the content,shape and particle size of copper conductive fillers and the type and content of coupling agents and diluents on the conductivity and bonding strength of organic conductive coatings were investigated.The changes of composition of organic conductive coatings before and after curing were analyzed.The conductive mechanism of the coating was clarified.The corrosion resistance of the organic conductive coating was evaluated by means of the polarization curve.The experimental results show that as the content of dendritic copper conductive filler increases,the conductivity of the coating increases first and then decreases.When the copper content is 55%,the conductivity of the coating is the best,0.11?/?;the conductivity of the organic conductive coating prepared by the dendritic copper conductive filler is much larger than that of the spherical copper conductive filler;the smaller the particle size of the spherical copper conductive filler and the dendritic copper conductive filler,the conductivity is better;When the silane coupling agent is 10%and the titanate coupling agent is 8%,the dispersion of the copper conductive filler in the epoxy resin is the best,and the conductivity of the organic conductive coating is the best;When the acetone content of the diluent is 3%and absolute ethanol content is 5%,the conductivity of the organic coating is the best.The conductivity of organic conductive coatings is the result of the synergy and competition between quantum mechanical tunneling and conductive channel theory.The corrosion resistance of the organic composite conductive coating is 0.19V,which is higher than that of the micro-arc oxidation ceramic coating,and the corrosion current density is also reduced by an order of magnitude,indicating that the corrosion resistance is significantly improved. |
PDF Full Text Request