| 摘要 |
PURPOSE:To synthesize cubic BN having a uniform grain size and a well-regulated grain shape in a high yield by blending Li3N and X3N2 (X is an alkaline earth metal) with an excess of hexagonal BN, heating the blend under specified conditions, and treating the resulting product at high temp. and superhigh pressure. CONSTITUTION:Li3N and X3N2 (X is an alkaline earth metal) are blended with hexagonal BN. The amount (mole) of the BN is 5-50 times the stoichiometric amount of BN required to produce LiXBN2 by a reaction represented by an equation Li3N+X3N2+3BN 3LiXBN2. The blend is brought into said reaction by heating to 700-1,100 deg.C in an inert atmosphere, and the resulting lumps are pulverized to obtain particles consisting of a catalyst component and hexagonal BN bonded together or mixed uniformly. The reaction product particles are optionally mixed with hexagonal BN, and they are premolded and treated at high temp. and superhigh pressure to synthesize cubic BN.
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