| Project/Area Number |
06452307
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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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 | HOKKAIDO UNIVERSITY |
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Principal Investigator |
MARUKAWA Kenzaburo Hokkaido Univ., Fac. of Eng., Prof., 工学部, 教授 (20001191)
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| Co-Investigator(Kenkyū-buntansha) |
TSUCHIYA Koichi Hokkaido Univ., Fac. of Eng., Research Assoc., 工学部, 助手 (50236907)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥7,300,000 (Direct Cost: ¥7,300,000)
Fiscal Year 1995: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1994: ¥4,900,000 (Direct Cost: ¥4,900,000)
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| Keywords | Shape memory effect / Martensitic transformation / Bainitic transformation / Electron microscopy / Interference fringe / Transformation strain / 電子顕微鏡観察 |
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| Research Abstract |
This research project was initiated by the present investigator's finding of new-type interference fringes in the transmission electron microscopy. The fringes appear in the image when a thin foil specimen containing thin martensitic plate is observed. These fringes have been found to originate from the transformation strain associated with the martensitic transformation. It has also been recognized that by measuring the fringe spacing (1) the transformation strain and (2) the thickness of the martensite plate can be estimated. To date, no convenient method has been known for precise measurement of the transformation strain, which is important in the application of the shape memory effect. Therefore, the purpose of the present study was to determine the transformation strain more precisely by utilizing new interference fringes.
The present study was started with the accurate formulation of the relation between the fringe spacing and the transformation strain under a given observation condition. Nextly, the transformation stain of bainites in Cu-alloy was determined. The obtained value was almost the same as the strain value of martensite in the same alloy. This finding is a strong support that the bainitic transformation proceeds by lattice shearing the same as the martensitic transformation. The transformation strain in Ti-Ni alloy martensite was also obtained.
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