| Project/Area Number |
17360341
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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 | Fukui University of Technology (2006-2007)
Osaka University (2005) |
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Principal Investigator |
KOBAYASHI Kojiro Fukui University of Technology, School of Engineering, Professor (70026277)
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| Co-Investigator(Kenkyū-buntansha) |
HIROSE Akio Osaka University, Graduate School of Engineering, Prof. (70144433)
SANO Tomokazu Osaka University, Graduate School of Engineering, Assi. Prof. (30314371)
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| Project Period (FY) |
2005 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥16,280,000 (Direct Cost: ¥15,500,000、Indirect Cost: ¥780,000)
Fiscal Year 2007: ¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000)
Fiscal Year 2006: ¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 2005: ¥10,300,000 (Direct Cost: ¥10,300,000)
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| Keywords | femtosecond laser / shocked high-pressure / ultra rapidly cooling / non-equilibrium material / amorphous structure / high-pressure phase / metallic glass / 衝撃波 / 超高圧 / 非平衡物質 |
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| Research Abstract |
Laser is absorbed, and thermal conduction occurs into the sample at supersonic velocities before mass has time to ablate. Ablation occurs and drives a mechanical shock into the material. Eventually the thermal front cools and its velocity drops below that of the following ablation shock. The shock front passes the thermal front and the shock then traverses unheated material. The amplitude of the shock pressure decreases continuously to zero with increasing propagation distance. However, the region behind the shock front remains in thermal equilibrium.
We found that non-equilibrium materials such as amorphous structure and high-pressure phases were synthesized using femtosecond laser pulses. A strong shock wave of which amplitude is 100-300 GPa is driven by the femtosecond laser ablation of metals. The cooling rate of the femtosecond laser induced-molten layer is estimated to be the order of 1013K/s. We appled these two features to synthesize non-equilibrium materials. After the femtosecond laser irradiation, crystalline structures were analyzed using XRD, TEM, and EBSD. Non-equilibrium materials which we succeeded to synthesize in this research project are follows ; CuTi amorphous alloy from g-CuTi alloy, high-pressure e-Fe from a-Fe, high-pressure b-Ti and w-Ti from a-Ti, hexagonal diamond from highly oriented pyrolytic graphite, high-pressure simple hexagonal structure of Si from diamond structure of Si.
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