Fabrication and characterisation of nickel coated Ni-NCZ (nickel coated ZrO 2 ) composite coating

Abstract

For the first time, electroless nickel plated ZrO₂ (Ni-NCZ) particles were used for the co-electrodeposition of Ni-NCZ composite coating. Optical microscope, SEM and X-ray diffraction studies showed that Ni-NCZ has a rough surface with a smaller Ni crystallite size than Ni-ZrO₂ due to the conductive properties of NCZ particles, which provide more nucleation sites for Ni clusters. The energy dispersive X-ray spectroscopy measurement results showed that Ni-NCZ has more co-electrodeposited particles than Ni-ZrO₂. This is due to the more positive zeta potential of NCZ particles compared to that of ZrO₂. The microhardness measurements demonstrated that the Ni-NCZ composite coating has a higher microhardness than Ni-ZrO₂ due to the higher amounts of co-electrodeposited particles and lower crystallite size. Electrochemical impedance spectroscopy and potentiodynamic polarisation test showed that the corrosion resistance of Ni-NCZ is higher than that of Ni-ZrO₂.