Synthesis of Ni/Co/Ni G Composite Coatings and Analysis of Their Corrosion Resistance Properties to Q235 Carbon Steel

摘要

In this work, nickel-modified graphene nanosheets (NiG) were prepared by hydrothermal method for the first time. The microscopic morphological analysis showed that the nickel nanoparticles were successfully reductively deposited on the surface of NiG with uniform distribution. NiG can be uniformly and stably dispersed in the electrodeposition solution. Then Ni/Co/NiG composite coating was prepared by pulsed current co-deposition method to provide corrosion resistance protection for Q235 carbon steel. The microstructure and morphology analysis of the composite coating shows that NiG were homogeneously incorporated in the coating and the composite coatings were uniform, dense and crack-free. The hardness test results showed that the doping of NiG improved the hardness of the composite coating. The influence of the added amount of NiG in the electrodeposition solution on the anti-corrosion performance of the composite coating was investigated. The electrochemical results illustrated that the composite coating prepared by adding 20 mL NiG dispersion achieved 98.04% protection efficiency (η_(EIS)) against carbon steel substrate in 3.5 wt.% NaCl solution, the Ni/Co/Ni-G20 composite coating has the best corrosion resistance.