Synthesis and characterization of Ni–Co/SiC nanocomposite coatings using sediment co-deposition technique

Abstract

SiC nano-particle reinforced Ni–Co alloy matrix nanocomposite coatings were electrodeposited in a modified Watt’s bath using sediment co-deposition (SCD) technique. The SiC nano-particle content and the microhardness of the Ni–Co/SiC nanocomposite coatings were investigated as a function of the electrodeposition parameters; such as the deposition current density (id), concentrations of the Co (CCo) and the SiC nano-particles (CSiC) in the bath and the electrolyte agitation rate (ar). The deposited coatings were characterized using scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and microhardness testing. CCo=50g/L and the CSiC=5g/L, id=3A/dm2 and ar=350rpm were determined as the optimum electrodeposition conditions to achieve the maximum microhardness. The highest microhardness was obtained for a coating containing 8.1vol.% SiC nano-particles and 55wt.% Co. Effects of the electrodeposition parameters on co-deposition behavior of the SiC nano-particles were discussed based on a co-deposition kinetic model. The variations in the microhardness of the coatings were explained based on the nano-structural details.