1987 Fiscal Year Final Research Report Summary
Quasicrystal formed in the undercooled aluminum melts
| Project/Area Number |
61550512
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
金属加工(含鋳造)
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| Research Institution | Kyoto University |
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Principal Investigator |
KOBAYASHI Kojiro Associate Professor Faculty of Engineering, Kyoto University, 工学部, 助教授 (70026277)
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| Co-Investigator(Kenkyū-buntansha) |
SHINGU Hideo Professor Faculty of Engineering, Kyoto University, 工学部, 教授 (20026024)
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| Project Period (FY) |
1986 – 1987
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| Keywords | quasicrystal / icosahedral phase / rapid solidification / five fold symmetry / Al-Mn alloy / Al-Mg system / 熱的安定性 |
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| Research Abstract |
Since an icosahedral phase(a species of quasicrystals)was discovered in an Al-Mn alloy by Schechtman et al. in 1984, the icosahedral pnase has been found in various systems, such as Al-(Cr, V, Ru, Mo and W). In almost cases, the technique of preparation was rapid solidificaiton.
Rapidly quenched Al-Mn alloys, with compositions in the range of 0 to 22at%mn were prepared by the single roller method. I phase was observed in the composition range of 8.8 to 22at%Mn. Upon annealing of Al-6.2at%Mn ribbon, I phase, precipitatea from supersaturated <alpha>, are observed at the temperature of593K by TEM and X-ray diffractions. The shape of I phase can be described as a dodecahedron with protuberances in the direction of the 20 three fold symmetry axes.
Quasicrystal like crystals have been detected in Al-Mg system. These are not characterized crystallographically , but they have quite similar structure.
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