| Project/Area Number |
07650771
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Physical properties of metals
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| Research Institution | Ehime University |
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Principal Investigator |
NAKAI Kiyomichi Ehime University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (60038114)
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| Co-Investigator(Kenkyū-buntansha) |
OHTSUBO Hiroyuki Ehime University, Faculty of Engineering, Research Associate, 工学部, 助手 (30036248)
OHMORI Yasuya Ehime University, Faculty of Engineering, Professor, 工学部, 教授 (10233280)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1996: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1995: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Superlattice / Intermetallics / Superalloy / Phase decomposition / Lattice defect / Solute atom / Age-haedening / SADT / 相分解過程 / マッシブ組織 / 結晶方位関係 / 析出前段階 / 相安定性 / 相分離 |
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| Research Abstract |
The mechanisms for decomposition processes of alpha-and beta-phases in Ti-Al base intermetallics have been analyzed in terms of crystallography.
1.the beta-phase stabilizes with increasing Zr and decomposes into Widmanstatten structure of alpha_2-phase by the Shear-Assisted Diffusional Transformation mechanism (SADT).
2.In 30-50at.%Al, (alpha_2+gamma) lamellar structure uncleates at the grainboundary gamma-allotriomorph by the SADT with the Blackburn orientation relationship.
3.Maasive structure, which consists of both alpha_2 and gamma, forms with the orientation relationships, {111}_<gamma>//{1011}_<alpha> and <110>_<gamma>//<1210>_<alpha>, in * 45at.%Al.
In Ni-base superalloy, the preprecipitation stages of ordered phases, which control the age-hardening, have been analyzed in terms of the interaction of solute atoms with lattice defects.
1.Quenched-in excess vacancies alter the nature of dislocations and enhance the trapping of solute atoms at the dislocations.
2.The trapping of solute atoms at the dislocations delays the ordered-phase precipitation as well as age-hardening, remarkably.
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