Investigation of (WAl)C-Co ceramic composites with the additions of fluoride solid lubricants: Preparation, mechanical properties and tribological behaviors

(WAl)C-Co/fluoride (CaF2, BaF2, CaF2/BaF2) self-lubricating ceramic composites prepared by mechanical alloying and hot pressing sintering was reported for the first time. The influence of the fluorides on the mechanical properties, friction coefficient and wear rate of the composites was also evaluated. The friction coefficient of the (W0.67Al0.33)C0.67-Co/fluoride materials is in the range of 0.22-0.36, with the wear rate in the order of 10− 6 mm3 N− 1 m− 1. The fluoride in the (W0.67Al0.33)C0.67-Co/fluoride plays a key role in decreasing the friction coefficient and wear rate. The wear layer formed during friction process exerts a significant influence on the tribological properties, which would increase the friction coefficient but protect the worn surface.