| Project/Area Number |
11555173
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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 | 展開研究 |
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| Research Field |
Structural/Functional materials
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| Research Institution | Osaka Prefecture University |
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Principal Investigator |
TAKASUGI Takayuki Osaka Prefecture University, Graduate School of Engineering Department of Metallurgy and Materials Science Professor, 工学研究科, 教授 (20108567)
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| Co-Investigator(Kenkyū-buntansha) |
HIRANO Toshiyuki National Institute for Materials Science Leader, 室長
YOSHIDA Mitsuhiko Miyagi National College of Technology, Department of Materials Science and Engineering Professor, 教授 (40042254)
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| Project Period (FY) |
1999 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥13,800,000 (Direct Cost: ¥13,800,000)
Fiscal Year 2001: ¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 2000: ¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 1999: ¥7,800,000 (Direct Cost: ¥7,800,000)
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| Keywords | Cr-base alloy / Laves alloy / Alloy design / High-temperature strength / Composite materials / Microstructure |
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| Research Abstract |
To develop Cr_2X (X : Nb, Zr, Hf, Ta and Ti)-based Intermetallic compound composites that have low-temperature fracture toughness and ultra high-temperature strength, and also are highly resistive to environment, the studies were performed. The following results were obtained.
1) Cr-Nb-W and Cr-Nb-Ti ternary alloy phase diagrams were constructed. The phase fields of Cr_2Nb Laves phase were determined. Also, it was determined that V substitutes for Cr sites while Mo, W and Ti substitute for Nb sites.
2) Microstructure and phase diagram of Cr-Zr binary alloy were investigated. Defect structures in Cr_2Zr were determined and discussed in association with atomic size concept. Also, the low-temperature fracture toughness, high-temperature compressive strength and oxidation behavior were investigated, discussed in relation to microstructure and defect structures, and also compared with those in other Laves alloys.
3) Deformation microstores of Cr_2Nb and V-added Cr_2Nb were investigated by TEM. It was shown that those alloys were deformable above 1300 K and deformation is not due to mechanical twinning but to glide/climb motion of dislocations.
4) Microstructure, low-temperature fracture toughness, high-temperature compressive strength and oxidation behavior of Cr_2Zr and Cr_2Nb alloys fabricated by powder metallurgy were investigated, and shown to be superior to those fabricated by ingot metallurgy.
5) Microstructure, phase diagram and low-temperature fracture toughness of Cr_2Zr-Cr_2Nb and Cr_2Zr-Cr_2Hf pseud binary alloys were investigated. The low-temperature fracture toughness was much improved at specific alloy compositions.
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