Electrodeposition of Ni-SiC nano-composite coatings and evaluation of wear and corrosion resistance and electroplating characteristics

Ni-SiC nano-composite coatings with different contents of SiC nano-particulates were prepared by means of the conventional electrodeposition in a nickel-plating bath containing SiC nano-particulates to be co-deposited. The dependence of SiC nano-particulates amount in the nano-composite coatings was investigated in relation to the SiC concentration in bath, cathode current density, stir rate and temperature of plating bath and it is shown that these parameters strongly affected the volume percentage of SiC nano-particulates. The deposition efficiency with and without SiC nano-particulate in bath was studied. The morphology and phases of the electrodeposited nano-composite were studied. The wear behavior of the nano-composite coatings was evaluated on a ball-on-disk test. The corrosion behavior of the nano-composite coatings was evaluated in the solution of 0.5 M NaCl at room temperature. It was found that the cathodic polarization potential increased with increasing the SiC concentration in the bath. The microhardness and wear and corrosion resistance of the nano-composite coatings also increased with increasing content of the SiC nano-particulate in bath. The SiC distribution in the nano-composite coatings at low concentrations of SiC in bath was uniform across the coatings, but at high concentrations, SiC nano-particulates on the surface were agglomerated. (C) 2007 Elsevier B.V. All rights reserved.