Investigation of pulse electrodeposited Ni–Co/SiO2 nanocomposite coating

Abstract

Ni–Co/SiO2 nanocomposite coating was deposited on the steel substrate by pulse electrodeposition method. The coatings were characterised by X-ray diffraction, field emission scanning electron microscopy technique, energy-dispersive X-ray spectroscopy and X-ray map (dispersive elemental mapping) analysis. The influences of stirring rate, pH and SiO2 concentration parameters on the mechanical properties and corrosion resistance were studied. The zeta potential of SiO2 nanoparticles was decreased by mounting the pH and also adsorption of the surfactant SDS. Microhardness, friction coefficient, wear and anodic polarisation were determined through Buhler microhardness tester, pin-on-disc wear test and potentiostat galvanic device, respectively. By applying optimum electrodeposition condition (stirring rate 200 rev min−1, pH 4.6 and SiO2 concentration 20 gL−1) incorporation of SiO2 particles into the nickel–cobalt matrix increases which results in the preparation of coatings with high microhardness and corrosion resistance, low friction coefficient and wear mass loss.