Fabrication and Corrosion Performances of Pure Ni and Ni-Based Coatings Containing Rare Earth Element Ce and Graphene by Reverse Pulse Electrodeposition

Pure Ni and Ni-based coatings containing rare earth element Ce and/or graphene were fabricated by reverse pulse electrodeposition. The influences of adding Ce and/or graphene on the electro-crystallization processes, the surface morphologies and the corrosion resistance of these composite coatings have been systematically studies and discussed using scanning electron microscope, Energy Dispersive Spectrometer, X-ray diffractometer, Raman, X-ray photoelectron spectroscopy and electrochemical measurements including electrochemical impedance spectroscopy and potentiodynamic polarization. The results showed that the incorporation of Ce and/or graphene into deposits significantly refined the microstructure and enhance the corrosion resistance of Ni deposits. Furthermore, a more apparent effect on improving corrosion resistance of coatings could be obtained by adding graphene than by adding Ce since graphene itself also owns the excellent anticorrosion property and impermeability except the refinement effect. Finally the best anticorrosion performance was observed in Ni-Ce-graphene coating perhaps due to the combined effects of Ce and graphene. (C) 2017 The Electrochemical Society. All rights reserved.