SYNTHESIS OF CUBIC BORON NITRIDE

摘要

PURPOSE:A mixture of hexagonal boron nitride with a catalyst is combined with cubic boron nitride at a specific ratio and they are held at specific temperatures and pressure to enable high-yield production of cubic boron nitride of desired particle size. CONSTITUTION:A mixture of hexagonal boron nitride and a catalyst such as Li3N.BN is combined with 1-10pts.wt. of cubic boron nitride of 15-65mum size per 100pts.wt. of the hexagonal boron nitride. The mixture is heated in a super high-pressure and high-temperature generator under such conditions as cubic boron nitride can exist with thermodynamic stability and the temperature is higher than the melting point of the catalyst and the pressure is lower than that where autogeneous nucleation of cubic boron nitride occurs. The process according to the present invention enables the high-yield production of cubic boron nitride of more than 65mum particle size which has larger demands. Further, this process can prolong the life of the pressure vessel of the facility.