| Project/Area Number |
05452272
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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 | University of Tsukuba |
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Principal Investigator |
MIYAZAKI Shuichi University of Tsukuba, Institute of Materials Science, Associate professor, 物質工学系, 助教授 (50133038)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥5,700,000 (Direct Cost: ¥5,700,000)
Fiscal Year 1994: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1993: ¥4,500,000 (Direct Cost: ¥4,500,000)
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| Keywords | Micromachine / Shape memory alloy / Ti-Ni / Microactuator / Martensitic transformation / Thin film |
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| Research Abstract |
Among several types of performance materials proposed for fabricating microactuators to power micromachines, Ti-Ni shape memory alloy thin films have great advantages such as large deformation and recovery force ; besides, even an intrinsic disadvantage of the shape memory alloy such as a slow response due to the limitation of cooling rate can be greatly improved in thin films. Therefore, the development of Ti-Ni shape memory alloy thin films has been keenly demanded. The present project has been successful in developing a perfect shape memory effect in sputter-deposited Ti-Ni thin films. The transformation temperatures and shape memory characteristics were found to be strongly affected by heat-treatment, alloy composition and sputtering condition. The shape change and recovery force associated with the martensitic transformation in Ti-Ni thin films reached up to 6% and 500Mpa, respectively, which were equivalent to those of bulk specimens.
Ti-Ni-Cu and Ti-Ni-Pd ternary shape memory alloy thin films were also made by sputtering. They showed a small temperature hysteresis and high transformation temperatures, respectively ; these characteristics are effective to achieve a high response actuator characteristic. The Ti-Ni-Pd thin film showed a single stage transformation upon cooling and heating similarly to a Ti-Ni binary alloy thin films. Corresponding, they showed a single stage deformation both upon cooling and heating. The Ti-Ni-Cu thin film showed a two-stage transformation and hence a two-stage deformation ; the first stage corresponds to the transformation between B2 and O(Orthorhombic)-phase and the second stage between the O- and M-phases. The first stage transformation was accompanied by a small temperature hysteresis. All these thin films showed perfect shape memory effect.
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