| 摘要 |
PCT No. PCT/JP92/01032 Sec. 371 Date Dec. 14, 1992 Sec. 102(e) Date Dec. 14, 1992 PCT Filed Aug. 12, 1992 PCT Pub. No. WO93/04012 PCT Pub. Date Mar. 4, 1993.A composite silicon nitride sintered body formed of silicon nitride as a matrix and silicon carbide having particle sizes of 5 to 500 nm as a phase dispersed in the sintered body, wherein the total amount of dispersed silicon carbide is 1 to 40% by volume based on the sintered body, the proportion by volume of the silicon carbide dispersed in the silicon nitride particles is 5 to 99% based on the total amount dispersed, the remainder being present only in the grain boundary of the silicon nitride, and a process for producing a silicon nitride composite sintered body which includes the steps of adding a sintering aid to amorphous composite powders as starting materials consisting of silicon, nitrogen and carbon to form a green compact; firing the green compact in a nitrogen atmosphere at 1350 DEG to 1650 DEG C. as the primary sintering; firing the same at 1600 DEG to 1900 DEG C. as the secondary sintering; and firing the same at 1800 DEG to 2200 DEG C. to transfer the silicon carbide precipitated in the particles of silicon nitride to the grain boundaries thereof.
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