| Project/Area Number |
02452235
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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 |
Physical properties of metals
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
YOSHINAGA Hideo KYUSHU UNIVERSITY,DEPARTMENT ON MATERIALS SCIENCE AND TECHNOLOGY,PROFESSOR, 総合理工学研究科, 教授 (40005856)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHIDA Fuyuki KYUSHU UNIVERSITY,DEPARTMENT OF MATERIALS SCIENCE AND TECHNOLOGY,RESEARCH ASSOCI, 総合理工学研究科, 助手 (30243968)
TUREKAWA Sadahiro KYUSHU UNIVERSITY,DEPARTMENT OF MATERIALS SCIENCE AND TECHNOLOGY,RESEARCH ASSOCI, 総合理工学研究科, 助手 (40227484)
NAKASHIMA Hideharu KYUSHU UNIVERSITY,DEPARTMENT OF MATERIALS SCIENCE AND TECHNOLOGY,ASSOCIATE PROFE, 総合理工学研究科, 助教授 (80180280)
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| Project Period (FY) |
1990 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥7,900,000 (Direct Cost: ¥7,900,000)
Fiscal Year 1992: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1991: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1990: ¥6,700,000 (Direct Cost: ¥6,700,000)
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| Keywords | grain boundary / interphase boundary / high-resolution transmission electron microscope / wire-bonding / molybdenum / silicon carbide / silicon nitride / EELS / ワイヤボンディング / アルミニウムー金合金 / シリコン / 炭化チタン |
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| Research Abstract |
Grain boundaries of single phase materials and interphase boundaries of composite materials are often responsible for the degradation of mechanical properties. In the present investigation, for molybdenum which has problems of grain boundary brittleness, ceramics of Si_3N_4, SiC and TiC which are hopeful as high-temperature structural materials, and micro-bonded Au-Al which is important in the IC industry, the grain boundary structure and interphase boundary structure have been observed by means of high-resolution transmission electron microscopy. Their boundary strength is discussed in connection with the boundary structure.
Symmetric tilt-boundary in Molybdenum: The fracture strength strongly depends on the grain boundary character in molybdenum. SIGMA 1 low angle and near SIGMA 3 coincidence boundaries have a good coherency, whereas the boundaries of misorientation angle around 30ﾟ are poor in coherency. However, the structure in those boundaries was found to be described by the grain-boundary dislocation model, It is considered that the grain boundary structure in molybdenum with a high covalency in bonding is not greatly different from that in normal metals.
Grain boundary structure of Si_3N_4, SiC and TiC: An amorphous-like layer was observed at grain boundaries in Si_3N_4 and SiC. That layer in SiC was analyzed by EELS using a micro beam technique. It is clarified that the layer is neither sintering aids nor impurity layer but a relaxed structure. A grain boundary layer such as observed in Si_3N_4 and SiC was not observed in TiC where the boundary structure was metal like.
Interphase boundary of micro-bonded Au-Al: In the foils prepared with a ultra-microtome no amorphous phase was observed, whereas in the foils prepared by ion milling a large part of the intermetallic compound formed on the interface was amorphous. Using the foils prepared with the microtome, the contamination effect on the bonding was clarified.
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