| Project/Area Number |
08555164
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Structural/Functional materials
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| Research Institution | Osaka University |
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Principal Investigator |
SABURI Toshio Faculty of Engineering, Osaka University, Professor, 工学部, 教授 (40029020)
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| Co-Investigator(Kenkyū-buntansha) |
GYOBU Atsuo Niihama National College of Technology, Associate Professor, 助教授 (20029896)
FUKUDA Takashi Faculty of Engineering, Osaka University, Research Associate, 工学部, 助手 (50228912)
KAKESHITA Tomoyuki Faculty of Engineering, Osaka University, Associate Professor, 工学部, 助教授 (90127209)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥10,700,000 (Direct Cost: ¥10,700,000)
Fiscal Year 1997: ¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1996: ¥8,200,000 (Direct Cost: ¥8,200,000)
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| Keywords | sputter-deposition / shape memory / thin film / Ti-Ni / micro-actuator / martensitic transformation / amorphus / R-phase |
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| Research Abstract |
(1) Composition and heat-treatment dependencies of the martensitic transformations in sputter-deposited shape memory Ti-Ni films were investigated by differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). Films were deposited on quartz substrates by sputtering using a target of an equiatomic TiNi alloy. The as-deposited films were found to be amorphous and to crystallize on heating above 750K.The amorphus films were heat-treated at various temperatures between 673 and 1123K and the transformation behaviors of the heat-treated films were examined by DSC and TEM.Obtained results are as follows. (1) During crystallization heat treatment, no precipitation occurs in near-equiatomic Ti-Ni films, whereas Ti2Ni particles precipitate in the Ti-rich films and Ti3Ni4 particles do in the Ni-rich films. (2) The B2*R transformation temperature becomes maximum (335K) at the equiatomic composition and decreases with increasing Ni-content with a rate of 96K/at % Ni in the range of 50.0-50.5at%Ni. It is constant (335K) in the Ti-rich side range of above 50.0at%Ti. It also is constant in the Ni-rich range of above 50.5at% Ni(287K with the films crystallized by holding at 773K).
(2) Martensitic transformation and associated two-way shape memory effect of sputter-deposited Ni-rich Ti-Ni alloy films were investigated. In the Ni-rich side of the Ti-Ni alloy phase diagram, B2 single phase region expands towards Ni-rich side and within the region B2*R transformation temperature decreases with increasing Ni-content. Specimens aged under constraint show two-way shape memory in association with the B2*R*B19' and the reverse transformations. While the hysteresis of the B2*R transformation is less than 2K,that of the B2*R*B19' is about 60K with the specimens aged under constraint. Aging at 673K under constraint gives the largest spontaneous shape change both for B2*R and B2*R*B19' transformations.
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