We tried to fabricate self-lubricant composite ceramics consisting of transition metal nitride (TiN or ZrN) matrixes and hexagonal boron nitride (h-BN) dispersions. Mixture powders were milled with a planetary ball mill for not more than 180 ks. Xray-diffraction patterns for the mixed powder showed that h-BN powder was finely grounded smaller than a submicron level and dispersed by the milling for longer than 36 ks. The pulse current pressure sintering (PCPS) method was employed to consolidate

more »

... he mixed powders. Sintered compacts consolidated under the pressure of 80 MPa and at 2073 K showed the highest density and hardness. The hardness of the sintered compacts decreased with the addition of BN of more than 5 mass%. This result suggests that the sintering of mixed powder could be strongly inhibited by the addition of h-BN. Relatively high density consolidation of more than 90% for single ZrN (or TiN) compact was obtained from the sintered compact of ZrN (or TiN) + 5mass% h-BN powders milled for 180 ks.