| Project/Area Number |
09450259
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Structural/Functional materials
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| Research Institution | Yokohama National University |
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Principal Investigator |
FUKUTOMI Hiroshi Yokohama National University, Faculty of Engineering, Professor, 工学部, 教授 (90142265)
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| Project Period (FY) |
1997 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥13,700,000 (Direct Cost: ¥13,700,000)
Fiscal Year 2000: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1999: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1998: ¥4,600,000 (Direct Cost: ¥4,600,000)
Fiscal Year 1997: ¥6,900,000 (Direct Cost: ¥6,900,000)
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| Keywords | lamellar microstructure / TiAl intermetallic compounds / texture / orientation control / reactive diffusion / 拡散反応 / 結晶集合組織 / 積層材料 / 反応焼結 / α単相領域 / Ti-46mol%Al |
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| Research Abstract |
Two basic processes designed for controlling the orientaion of lamellar microstructure of with the constituents of α_2+γ phases in the TiAl based alloys are theoreticall and experimentally examined. The first process consists of the high-temperature deformation in α single phase region followed by the annealing and deformation in α_2+γ region. The uniaxial compression in the α single phase region resulted in the formation of a fiber texture, though dynamic recrystallization occurred. The maximum pole density for the compression plane appeared about 35 degrees away from(0001)of α_2 phase. The heat treatment generates the lamellar microstructure reflecting the texture formed by the uniaxial deformation in the α single phase region. Work softening was observed at the deformation of the specimen with fully lamellar microstructure formed by the deformation in the α single phase region and the annealing in the two phase region. The deformation in the two phase region brought about the rotation of the lamellae. The lamellar interface lied almost parallel to the compression plane after the deformation of about-0.8 in true strain.
The second process is designed on the basis of the reactive diffusion between the textured titanium foils and aluminum foils. Thermal process consists of four heating stages and a cooling stage for lamellar construction. The phases are examined after the heat treatments by EDX.It was found that 40-60% of the orientations of the lamellae are dominated by the texture of the starting titanium foils. It was concluded that the combination of the reactive diffution process and the thermomechanical treatment described above is promising for the manufacturing process of TiAl sheet materials with the oriented lamellar microstructure.
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