Preparation and properties of electroplating zinc-nickel alloy/organic aluminum-rich composite coatings on carbon steel surface
In order to improve the protection performance and application restrictions of galvanized nickel alloys on the surface of carbon steel,the electroplating zinc-nickel layer was used as the bottom layer,and the organic aluminum coating was used as the top layer to design a composite coating protection system.The surface/section of the surface/section of the composite coating of electroplating nickel/organic aluminum coating and analysis.The surface/cross section morphology and corrosion resistance of Ni/Al composite coatings were characterized and analyzed by means of scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),neutral salt spray test and electrochemical test.The results show that the surface of the organic aluminum coating is smooth and flat,without obvious defects.The composite coating system interface is well-combined and there is no layered phenomenon.After 1500 h neutral salt fog test,the composite coating is not red rust.The corrosion current density of the composite coating is 2 orders lower than that of the single electro Zn-Ni alloy layer,and the composite coating shows excellent protective performance,which will realize the application in the field of Marine protection.The composite coating has a higher corrosion resistance compared to the separate electroplating Zn-Ni alloy layer,which effectively solves the protection limit of electroplating nickel alloys in applications.