TRIBOLOGICAL INVESTIGATION OF BORON CARBIDE FILMS SLIDING AGAINST DIFFERENT MATING MATERIALS UNDER HIGH RELATIVE HUMIDITY

Tribological performances are significantly affected by the tribo-chemical reaction of the mating materials, while the effect on the B 4 C film under high relative humidity conditions are poorly investigated.Therefore, fiction tests of three tribo-pairs (B 4 C/WC, B 4 C/steel and B 4 C/Al 2 O 3 ) under 85 % RH with various normal loads and sliding frequencies were performed.The results show that the B 4 C/WC tribo-pair exhibits excellent tribological properties, including very stable friction curves, minimum friction coefficients & wear rates, maximum carrying-load capacity and the smallest fluctuations with the change of the normal load.Similar results have been obtained for the B 4 C/WC tribo-pair with the increase in the sliding frequency.This is mainly attributed to the oxidation of WC to form WO 3 that is conducive in enhancing the tribological performances.Therefore, the sliding contact of B 4 C/WC is the desirable design for engineering applications under high relative humidity.