Microstructure of Ni/WC surface composite on a copper substrate

This paper reports the researching work which investigated the microstructure and hardness of the surface infiltrated composite (WC/Ni) layers produced on copper substrates. The surface infiltrated composite layers were produced by a vacuum infiltration casting technique (VICT) using Ni-based composite powder with different WC particles content as raw materials. With an appropriate choice of processing condition, a compact infiltrated layer was achievable and this was conformed through a scanning electron microstructure (SEM). The infiltrated layer includes a surface composite layer and a transition layer, and the thickness of the transition layer decreases with the increasing content of WC. The surface macro-hardness and micro-hardness of the infiltrated layer had been evaluated. The macro-hardness of the layer is about HRC60.0 and the distribution of micro-hardness presents gradient change. The average micro-hardness of the infiltrated layer is about HV800.