Tribological behaviors of B4C-hBN ceramic composites used as pins or discs coupled with B4C ceramic under dry sliding condition

Used as pin or disc specimens, the tribological behaviors of hot-pressed B4C-hBN ceramic composites containing different contents of hBN (0, 5, 10, 20 and 30 wt%) coupled with B4C ceramic under dry sliding condition have been investigated using a pin-disc tribometer. Experimental results show that, the dry sliding tribological behaviors of B4C-hBN ceramic composites against B4C are obviously different when B4C-hBN ceramic composites are used as pin or disc specimens, respectively. When B4C-hBN ceramic composites are used as pin specimens, with hBN content increasing, the friction coefficients of B4C-hBN/B4C pairs gradually increase; however, when B4C-hBN ceramic composites are used as disc specimens, with hBN content increasing, the friction coefficients of B4C/B4C-hBN pairs gradually decrease. The reasons that cause the discrepancy are discussed.