| Project/Area Number |
13450261
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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 |
Physical properties of metals
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| Research Institution | Kumamoto University |
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Principal Investigator |
KAWAMURA Yoshihito Kumamoto University, Department of Engineering, Professor, 工学部, 教授 (30250814)
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| Co-Investigator(Kenkyū-buntansha) |
ANDO Shinji Kumamoto University, Department of Engineering, Associate Professor, 大学院・自然科学研究科, 助教授 (40222781)
OTOMO Toshiya High Energy Accelerator Research Organization, J-PARC Project Office, Research Associate, 高エネルギー加速器機構物質構造科学研究所, 助手 (90270397)
NISHIDA Minoru Kumamoto University, Department of Engineering, Professor, 大学院・自然科学研究科, 教授 (90183540)
MIURA Hideshi Kumamoto University, Department of Engineering, Associate Professor, 大学院・自然科学研究科, 教授 (30117254)
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| Project Period (FY) |
2001 – 2003
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| Keywords | supercooled liquid / viscosity / amorphous alloy / metallic glass / glass transition / 自由体積 / 緩和 / フラジリテイー |
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| Research Abstract |
(1)Constitutional equations showing the temperature and strain rate dependence on the viscosity were established using a stretched exponential function for supercooled liquids of La_<55>Al_<25>Ni_<20>, Zr_<65>Al_<10>Ni_<10>Cu_<15>, Pd_<40>Ni_<40>P_<20> and Pt_<60>Ni_5P_<25>. The coefficient of the stretched exponential function of the metallic supercooled liquids was in the ranging from 0.82 to 0.90, showing higher uniform structure than polymer supercooled liquids.
(2)The fragility of the metallic supercooled liquids was 54,46,35 and 30 for Pd_<40>Ni_<40>P_<20>, Pt_<60>Ni_5P_<25>, La_<55>Al_<25>Ni_<20> and Zr_<65>Al_<10>Ni_<10>Cu_<15>, respectively. The metal-metalloid supercooled liquids of the Pd_<40>Ni_<40>P_<20> and Pt_<60>Ni_5P_<25> exhibited more fragile than the metal-metal supercooled liquids of the La_<55>Al_<25>Ni_<20> and Zr_<65>Al_<10>Ni_<10>Cu_<15>. The metallic supercooled liquids had an intermediate fragility between the strong liquid of SiO2 and the fragile liquid of o-terphenyl.
(3)Although the famous Vogel-Fulcher-Tammann relation gave a good description of the metallic supercooled liquid in the neighborhood of the glass transition temperature, sufficient description of the viscosity was not obtained both for supercooled liquid and melt. The equilibrium viscosity over the entire temperature range can be well fitted by the Cohen-Grest free-volume relation.
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