Tribological behavior of WC-Al₂O₃-graphene composite at different temperatures

WC-Al2O3-graphene composite powder was synthesized by ultrasonic treatment and ball milling, then consolidated by hot pressing sintering (HPS). For potential applications, the friction coefficient and wear resistance of the sintered bulks at different temperatures (room temperature, 200, 400, and 600°C) were investigated. The wear tracks were characterized by scanning electron microscope, energy dispersive spectroscopy and Raman spectroscopy, X-ray photoelectron spectroscopy, respectively. The results show that the friction coefficient decreases and the wear rate increases with the increase of temperature, mainly because oxidization wear occurs on the wear surface of WC-Al2O3-graphene composite under high temperature. The main wear mechanism is the destruction and formation of tribochemical compacted layer. Graphene reduces the wear rate of WC-Al2O3-graphene composite under high tampere. The reason is that graphene reduces oxidation wear by blocking or absorbing oxygen; moreover, graphene reduces the cycle frequency of damage and reconstruction of tribochemical compacted layer by reducing the peeling of it.