1990 Fiscal Year Final Research Report Summary
Preparation of Cubic Boron Nitride/Diamondo Nanocomposite from CVD Materials by Very High Pressure Treatment
| Project/Area Number |
01470068
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
無機工業化学
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| Research Institution | Tohoku University |
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Principal Investigator |
HIRAI Toshioo Institute for Materials Research Professor Tohoku University, 金属材料研究所, 教授 (50005865)
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| Co-Investigator(Kenkyū-buntansha) |
OMORI Mamoru Institute for Materials Research Research associate Tohoku University, 金属材料研究所, 助手 (30005954)
MASUMOTO Hiroshi Institute for Materials Research Research associate Tohoku University, 金属材料研究所, 助手 (50209459)
SASAKI Makoto Institute for Materials Research Research associate Tohoku University, 金属材料研究所, 助手 (70187128)
YAMANE Hisanori Institute for Materials Research Research associate Tohoku University, 金属材料研究所, 助手 (20191364)
ONODERA Akifumi Faculty o Engineering Science Assistant professor Osaka University, 助教授 (20029523)
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| Project Period (FY) |
1989 – 1990
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| Keywords | Cubic boron nitride / Diamond / Very high pressure treatment / Composite / CVD / Nanocomposite / Dielectric property / Substitute solide solution |
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| Research Abstract |
The cubic, zincbiende from of boron nitride (cBN) is a very intriguing material with a high hardness, thermal conductivity, as well as refractivity, all next ot diamond. This work aimed at developing a cBNーdiamond composite by combination of CVD/high pressure techniques.
Two CVD^. d samples, BN (97) - C (3) and BN (20) - C (80), were subjested to high pressures to 10 GPa and high temperatures to 1700^ﾟC. From BN (97) - C (3), cBN appeared above 6 GPa and 1600^ﾟC or above 8 GPa and 1400^ﾟC. No diamond was formed at any conditions studied. From BN (20) - (80), a coexistence of cBN and diamond was observed at 10 GPa and 1600^ﾟC. Lowering of pressure at this same temperature. 1600^ﾟC, resulted in disappearance of diamond. Elevation of temperature to 1700^ﾟC at 8 GPa could however render sample partly convert into diamond.
In reference to the existing phase relations of boron nitride and carbon, the present study has clarified two important points : First, diamond can be formed at 8 GPa which is unexpectedly low for noncatalytic condition. Second, the temperature required for cBN formation exhibits upward shift with incorporation of carbon.
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