| 摘要 |
PROBLEM TO BE SOLVED: To convert hexagonal system boron nitride into cubic system boron nitride with excellent cutting property by keeping hexagonal boron nitride in specified temperature and pressure conditions in the presence of carbides of alkali metals or alkaline earth metals and converting hexagonal system boron nitride into cubic boron system nitride. SOLUTION: To synthesize cubic system boron nitride which is preferably used as a grinding, polishing, and cutting material from hexagonal system boron nitride, the hexagonal system boron nitride is kept in temperature and pressure conditions within ranges where the cubic system boron nitride is stable in the presence of one or more carbides of alkali metals and alkaline earth metals and one or more amides and imides of alkali metals and alkaline earth metals to convert the hexagonal system boron nitride into cubic system boron nitride. As the carbides of alkali metals and alkaline earth metals, Li2 C2 , etc., is basically used and as amides and imides of alkali metals and alkaline earth metals, LiNH2 , NaNH2 , etc., are basically used and, even in the case their solid solution is used, the same effect is obtained. |
