| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a SiC-BN composite sintered compact exhibiting no color unevenness, and being good in processability, strength and heat resistance. <P>SOLUTION: The SiC-BN composite sintered compact contains 10 to 40 mass% of boron nitride, 58 to 88 mass% of silicon carbide and 0.5 to <3 mass% of boron carbide or boron carbide and carbon, and has a relative density of ≥97%, a bending strength of ≥300 MPa, and a mass loss rate of ≤0.6 mass% after 10-hr heating at 2,000°C in Ar gas. The method for manufacturing a SiC-BN composite sintered compact includes hot-press sintering a mixed powder in a non-oxidizing atmosphere at a pressure of 10 to 50 MPa at a temperature of 1,850 to 2,150°C for a holding time of 1 to 6 hours, the mixed powder containing 10 to 40 mass% of the boron nitride having a specific surface area of ≥10 m<SP POS="POST">2</SP>/g and an oxygen content of 18.5×(a BN mass% in the mixed powder)<SP POS="POST">-0.657</SP>, 58 to 88 mass% of the silicon carbide having a specific surface area of ≥7 m<SP POS="POST">2</SP>/g, and ≥0.5 to <3 mass% of boron carbide or boron carbide and carbon, and having an oxygen amount of ≤1.20 mass%, and a specific surface area of 8 to 45 m<SP POS="POST">2</SP>/g. <P>COPYRIGHT: (C)2012,JPO&INPIT |
