Electrodeposition and heat treatment of nickel/silicon carbide composites

Electrodeposited Ni/SiC composite coatings were obtained in a Watts-type bath. The effect of fine SiC particles on polarization curves of the cathodic reduction of nickel ions was discussed. The incorporation of the particles into the deposit with respect to current density and SiC concentration in the bath was tested. Cathodic current efficiencies were also calculated. Structure of as-plated and heat-treated Ni/SiC composites were examined by means of metallography observations as well as scanning and transmission electron microscopy methods. Two phase transformations in the temperatures range of 20–700 °C were found. For annealed samples, Ni2Si and Ni3Si2 phases were identified. Hardening of the Ni/SiC composites as a function of the particle content in the deposit and annealing temperature was determined by means of the microhardness testing method.