| 摘要 |
PURPOSE:To synthesize cubic boron nitride at low temperature and pressure, by mixing powders of hexagonal boron nitride and synthesizing catalyst for cubic boron nitride, heat-treating them in a reducing atmosphere to remove improprieties therefrom, thereafter forming, pressurizing and heating them under a specific condition. CONSTITUTION:Powders of hexagonal boron nitride(HBN) and synthesizing catalyst for cubic boron nitride are mixed to prepare mixed powders, which mixed powders are heat-treated in a reducing atmosphere to remove such impurities as oxides, etc., therefrom, or after which heat-treatment, heat-treatment is conducted in an atmosphere of nitrogen, thereafter, by application of pressure and heat thereto within a region wherein cubic boron nitride(CBN) remains stable, cubic boron nitride is synthesized. In the case that said synthesizing catalyst for CBN is metal, said catalyst is converted to nitride or boron nitride, thereby these mixed powders are prepared. As synthesizing catalysts for CBN, alkaline earth metals, alkali metals, and nitrides or boron nitrides thereof are cited. |
