| Project/Area Number |
01302054
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| Research Category |
Grant-in-Aid for Co-operative Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
Physical properties of metals
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| Research Institution | Kyoto University |
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Principal Investigator |
KOIWA Masahiro Kyoto University, Department of Metal Science and Technology, Professor, 工学部, 教授 (00005860)
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| Co-Investigator(Kenkyū-buntansha) |
OTSUKA Kazuhiro University of Tsukuba, Institute of Materials Science, Professor, 物質工学系, 教授 (50029881)
SHIMIZU Kenichi Osaka University, The Institute of Scientific and Industrial Research, Professor, 産業科学研究所, 教授 (60029832)
HIRAGA Kenji Tohok University, Institute for Materials Research Professor, 金属材料研究所, 教授 (30005912)
NITTONO Osamu Tokyo Institute of Technology Department of Metallurgical Engineering, Professor, 工学部, 教授 (40016564)
INO Hiromitsu University of Tokyo, Department of Materials Research, Professor, 工学部, 教授 (20029466)
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| Project Period (FY) |
1989 – 1990
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| Keywords | Martensitic transformation / Banitic transformation / Shape memory alloys / Quasic crystals / Intermetallic compounds / Phase transformation |
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| Research Abstract |
Mechanisms of Phase transformations in various material have been studied with a variety of advanced experimental techniques. Some examples of the results obtained in this Cooperative Research are briefly described below.
1. Structural and lattice dynamical investigations have been performed on the intermetallic compounds : NiAl, ZrNb and FePd, by neutran diffraction and scattering experiments. Structural fluctuation in mesoscopic scale is found near the temperature of transformation from the bcc- to the martensitic phase. This fluctuation is termed the heterophase fluctuation, which is believed to be characteristic of the martensitic transformation.
2. A combination of the Imaging Plate and a synchrotron-radiation source has been shown to be powerful for the observation of changes in the two-dimensional intensity distribution of diffuse scattering. X-ray diffuse scattering from an AgZn single crystal having the B2-type structure were observed successively during the structural transition from the beta' phase to the zata phase. It has been shown in a series of patterns taken at a time interval of 600s that a diffuse intensity sheet extending parallel to the (111) relplane gradually loses its intensity without a precursive modulation while weak diffraction spots from the nuclei of the zeta phase appear superimposed on the sheet with a definite positional relation to the diffraction spots from the beta' phase promising aspects as well as the limits of the method applied to time-resolved measurements of structural changes are discussed.
3. ALCHEMI(Atom Location by Channeling Enhanced MIcroanalysis) has been successfully applied for determination of site occupancies of Cu and Zn atoms in a shape memory alloy of Cu-21Au-45Zn (at. %) ; Zn atoms occupy the body-center sites, and Cu atoms the corner sites.
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