Crystal Structure and Phase Stability of Intermetallic Compounds
| Project/Area Number |
04239103
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| Research Category |
Grant-in-Aid for Scientific Research on Priority Areas
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| Allocation Type | Single-year Grants |
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| Research Institution | Hokkaido University (1993)
Tokyo Institute of Technology (1992) |
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Principal Investigator |
SUZUKI Tomoo Hokkiado University, Dept.of Mat.Engr., Professor, 工学部, 教授 (80016782)
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| Co-Investigator(Kenkyū-buntansha) |
MOHRI Tetsuo Hokkaido University, Dept.of Mat.Engr.Associate Professor, 工学部, 助教授 (20182157)
MORINAGA Masahiko Nagoya University, Dept.of Mat.Sci.and Engr., Professor, 工学部, 教授 (50126950)
NAKAYAMA Yutaka University of Osaka Prefecture, Dept.of Metallurgy and Met.Sci., Professor, 工学部, 教授 (90081364)
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| Project Period (FY) |
1992 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥73,500,000 (Direct Cost: ¥73,500,000)
Fiscal Year 1993: ¥30,000,000 (Direct Cost: ¥30,000,000)
Fiscal Year 1992: ¥43,500,000 (Direct Cost: ¥43,500,000)
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| Keywords | phase stability / Structure Map / DV-Xalpha calculation / CVM / Al_3Ti / CoAl / ductility / thermal conductivity / 金属間化合物 / 合金設計 / 状態図 / 第一原理計算 / 機械的性質 / 結晶構造 / 電子論 / 平衡状態図 |
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| Research Abstract |
The main objectives of the present project are to predict and to control a crystal structure and a microstructure of a given intermetallic compound (imc) based on the sound theoretical analysis. As potential theoretical tools, we adopted the electronic structure calculation based on the molecular orbital method and Cluster Variation Method of statistical mechanics. The former was utilized to construct a "Structural Map" in which a stability region of a particular crystal structure is specified. The latter is combined with the ab initio internal energy calculation to obatain a phase diagram of an alloy system in which an imc of interest appears. These theoretical efforts are reflected in the folowing experimental achievments.
1. Various alloying elements were found to stabilize the L12 ordered structure for the Al3Ti imc which is characterized by a D022 structure in its binary state. Among the alloying elements, it was confirmed that Cr and Mn were most effective in improving the ductility.
2. The phase diagrams are established for ternary and quartery systems based on Ni-Al and Co-Al binary systems, and the improvement of mechanical properties was attempted in the multiphase region of the phase diagram. Ni3Al-NiBe and Co3Ti-Ni3Al are the succesful examples for which ductility is endowed.
In addition, measurements of thermal conductivity are systematically performed for a series of intermetallic compound.
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Report
(3 results)
Research Products
(18 results)
