Microstructure and tribological performances of W-Cu-Co-xWC alloys with various WC amounts

In this work, W-Cu-Co-xWC (x = 0, 0.5, 1.5, 2.5, 3.5) alloys were prepared by the activation liquid phase sintering method. The effects of WC doping on the structure and performances of W-Cu-Co alloys were studied using a scanning electron microscope, X-ray diffraction analyzer, energy dispersive spectroscopy, Vickers hardness tester, conductometer, friction and wear machine, and three-dimensional profilometer. Adding an appropriate amount of WC could promote the homogeneous distribution of Cu in the W-skeleton, reducing the internal blockage and improving the densification degree of W-Cu-Co alloys. Compared with W-Cu-Co alloys, W-Cu-Co-1.5WC alloys presented the best comprehensive properties, with a relative density of 98.65%, hardness of 258 HV, and conductivity of 38.1% IACS. Meanwhile, the addition of a small amount of WC could significantly enhance the tribological properties of W-Cu-Co alloys. When the doping amount of WC ranged from 0.5 wt.% to 2.5 wt.%, the wear rate was reduced by over 60%, and the average friction coefficient was lowered by over 19%. However, when the doping amount of WC exceeded 2.5 wt.%, its density and hardness were decreased, resulting in a decrease in wear resistance.