| Project/Area Number |
18560687
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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 |
Material processing/treatments
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| Research Institution | Tohoku University |
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Principal Investigator |
KIMURA Hisamichi Tohoku University, Institute for Materials research, Tohoku University, Associate Professor (00161571)
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| Co-Investigator(Kenkyū-buntansha) |
INOUE Akihisa Tohoku University, President (10108566)
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| Project Period (FY) |
2006 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥3,810,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥510,000)
Fiscal Year 2007: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
Fiscal Year 2006: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | quasicrystalline / aluminum alloy / melt quenching / powder metallurgy / high temperature strength / Al合金 / アルミニウム合金 |
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| Research Abstract |
Abstract of contents: Alloy design policies of Al-base alloys with high temperature strength was as follows: 1) Atomic sizes of composition elements should be widely different, 2) Alloys should be multi-components, 3) Heat of mixing among main component elements should be negative and 4) Added elements should have lower diffusion coefficient. As a result, we found that a liquid quenched Al-Fe-Cr-Ti-Co-Mo alloy system have a certain composition range where the fine particles of quasi-crystals are dispersed in fcc-Al phase.
Rapidly quenched alloy powder of the above composition (content of Al was 93-95 at%) was solidified by PM under conditions of extrusion temperature = 673 K and extrusion ratio = 11. The high temperature strength of thus prepared PM alloy was excellent showing the tensile strength (σuts) of >300 MPa and >150 MPa at 573 K and 673 K, respectively. Transmission electron microscopy (TEM) showed that quasi-crystallites of about 100 nm in size with high temperature stability and high hardness were dispersed in the fcc Al-phase. The high temperature strength was attributed to the structure observed by TEM. Especially, ours of Al_<93>Fe_<2.45>Cr_<2.45>Ti_<0.8>Co_<0.8>Mo_<0.5> alloy was very high, that is, 364 MPa and 203 MPa at 573 K and 673 K, respectively.
Significance= The target figure of the high temperature strengh of Al-alloy was >300 MPa at 573 K. The high temperature strengh of Al_<93>Fe_<2.45>Cr_<2.45>Ti_<0.8>Co_<0.8>Mo_<0.5> alloy PM material developed by present research is much higher the figure, and therefore, we attained the purpose.
Importance: This developed Al-alloys having light-weight and high temperature strength can be used for the high temperature part of the transportation machines to seek the fuel cost improvement. And therefore, this developed Al-alloys are very important materials as one of candidate for the environmental problems solution.
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