| 摘要 |
PURPOSE:To synthesize high-hardness boron nitride free from a film fault and impurities contents by preliminarily heating a gaseous mixture of gas contg. boron atom, gas contg. nitrogen atom and hydrogen by radiation of electron beams and thereafter introducing it onto the surface of a heated base plate. CONSTITUTION:A gaseous mixture of gas contg. boron atom, gas contg. nitrogen atom and hydrogen supplied from a reaction gas feeder 3 is fed into a reaction tube 6 via a feed pipe 9. This gaseous mixture is preliminarily heated by a thermion emitting material 10 such as a tungsten filament heated at >=1,000 deg.C and the gases are made to an excited state. The heated gaseous mixture is introduced onto the surface of a base plate 12 heated at 300-2,000 deg.C and both gas contg. boron atom and gas contg. nitrogen atom are pyrolytically decomposed and allowed to react with each other to deposit cubic boron nitride. This cubic boron nitride is excellent in thermal shock resistance, thermal conductivity, hardness and abrasion resistance and also durability for metal of iron group at high temp.
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