FORMATION OF CUBIC C-BN BY CRYSTALLIZATION OF NANO-AMORPHOUS SOLID ATATMOSPHERE

An amorphous carbon-boron nitride (C-BN) solid was prepared by ball mi lling the mixture of graphite and hexagonal BN powders for a period of 120 h, After annealing the amorphous C-BN solid for 1 h at atmosphere in the temperature range from 800 to 900 K and then quenching it to r oom temperature, a small amount of cubic C-BN solid solutions with dia mond-like structure, which belong to a high energy phase and can only be synthesized previously under high pressure and temperature (30 GPa, 2000 K), were observed in the annealed amorphous C-BN solid. The latt ice constant of the cubic C-BN solid solution was 0.3587 nm, and its g rain size was in the range of 10 to 50 nm.