Electrodeposited Ni/SiC nanocomposite coatings and evaluation of wear and corrosion properties

Ni/SiC nanocomposite coatings were obtained by electrochemical codeposition of SiC nanoparticles with nickel, from an additive-free Watts type bath. Pure Ni deposits were also produced under the same experimental conditions for comparison. The influences of the SiC nanoparticle concentration in the plating bath, the current density and the stirring rate on the composition of nanocomposite coatings were studied. It is shown that these parameters strongly affected the weight percentage of SiC nanoparticulates. The phase structures, the surface morphology, and the chemical composition of the coatings were characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive spectroscopy (EDS) respectively. The corrosion performance of the coatings was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods. The wear resistance and the microhardness of the coatings were studied also on a ball-on-disk tribometer and Vickers hardness tester, respectively. Characterization experiments showed that the SiC nanoparticle incorporation promoted changes in the texture of the nickel matrix. Moreover, the presence of SiC inhibits Ni growth, enhances re-nucleation, and hence results in a microcrystalline metal matrix. The results revealed that Ni/SiC nanocomposite coating provided excellent anti-corrosion performance and presented higher microhardness and better anti-wear performance compared to pure Ni coating.