Nanostructured Ni–WC–Co composite coatings fabricated by electrophoretic deposition

Abstract

Electrophoretic deposition (EPD) was applied to the fabrication of nanostructured Ni–WC–Co composite coatings on nickel-plated stainless steel substrates. The micro-hardness and ball-on-disk sliding wear of the sintered composite coatings were tested for, and the results correlated to those of the microstructure analysis, which was determined by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Sintering after EPD on the substrates and high-pressure pressing resulted in dense composite coatings containing high volume fractional of nanostructured WC or WC–Co particles. Compared with pure nickel coatings or stainless steel, the coatings containing nanostructured WC–Co particles showed a significant increase in hardness and wear resistance. The remarkable improvement in hardness and wear resistance is attributed to the dispersion hardening of nanostructured WC–Co particles in the composite coatings.