Deposition characteristics, microstructure and wear behaviour of Co–WC composite coatings

Abstract

ABSTRACT The purpose of this work is to investigate the microstructure and mechanical properties of a novel WC-reinforced Co matrix composite coating synthesized by pulse electrodeposition technique with various duty cycles. The growth and wear mechanisms for Co–WC composite coating were explored. The microstructure, morphologies and composition of the composite coating were characterized by X-ray diffractometer (XRD) and scanning electron microscopy (SEM) equipped with energy-dispersive spectroscope (EDS). Results illustrated that the Co–WC composite coating fabricated at duty cycle of 50% achieved dense structure and high WC incorporation. Also, the composite coating exhibited the lowest friction coefficient and mass loss, which was mainly ascribed to the interlocking effect between protrusions and the ‘pinning effect’ of hard particles in the matrix metal. As the duty cycle was increased to 60%, the micro-indentation hardness of Co–WC composite coatings increased to the maximum value of 587 HV.