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

摘要

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 electro-deposition parameters; such as the deposition current density (i_d), concentrations of the Co (C_(Co)) and the SiC nano-particles (C_(Sic)) in the bath and the electrolyte agitation rate (a_r). The deposited coatings were characterized using scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and microhardness testing. C_(Co) = 50 g/L and the C_(sic) = 5 g/L, i_d = 3 A/dm2 and a_r = 350 rpm were determined as the optimum electrodeposition conditions to achieve the maximum microhardness. The highest microhardness was obtained for a coating containing 8.1 vol.% SiC nano-particles and 55 wt.% 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.