| Project/Area Number |
06453081
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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 |
Composite materials/Physical properties
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| Research Institution | Tohoku University |
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Principal Investigator |
GOTO Takashi Tohoku University, Institute for Materials Research, Associate Professor, 金属材料研究所, 助教授 (60125549)
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| Co-Investigator(Kenkyū-buntansha) |
MASUMOTO Hiroshi Tohoku University, Institute for Materials Research, Research Associate, 金属材料研究所, 助手 (50209459)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥4,800,000 (Direct Cost: ¥4,800,000)
Fiscal Year 1995: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1994: ¥3,600,000 (Direct Cost: ¥3,600,000)
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| Keywords | Boron Carbide / Titanium Boride / Silicon Carbide / Eutectic Reaction / Boron-rich Borides / Functionally Graded Material / Microstructure / Thermoelectric Figure of Merit / 熱電性能 / 性能指数 |
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| Research Abstract |
Boron carbide (B_4C) is a good candidate material for high-temperature thermoelectric conversion at more than 1200K.In the present study, we tried to improve the thermoelectric performance of B_4C by controlling microstructure making B_4C-based composites. Firstly, we prepared SiC-B_4C composites by arc-melting., since SiC has good oxidation resistance and superior thermoelectric properties. A typical lamella texture was observed at SiC content of 40 to 50 mol%, and we confirmed that SiC-B_4C composites are a quasi-binary system. The optimum SiC content was 40 mol%, and its thermoelectric figure of merit value (ZT) was about 0.1 at T=1100K.Secondary, we found that the dispersed phase in the B_4C should be highly electrically conductive in order to improve the thermoelectric performance. Then we prepared TiB_2-B_4C composites. The TiB_2-B_4C composites are also a quasi-binary system. The lamella texture was observed at TiB_2 content of 15 to 25 mol%. The highest ZT values was attained at TiB_2 content of 6 mol%, and its ZT value was 0.5 at T=1100K.This value is almost equivalent to the required level for practical thermoelectric devises.
The next issue which we should try is to develop a functionally graded thermoelectric materials which consist of the TiB_2-B_4C composites, Si-Ge alloys, PbTe and Bi_2Te_3.
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