2019 Fiscal Year Final Research Report
A study of beta titanium superelastic alloys with small transformation stress change during cyclic deformation
| Project/Area Number |
17K14833
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Structural/Functional materials
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
Shinohara Yuri 東京工業大学, 科学技術創成研究院, 助教 (30755864)
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| Project Period (FY) |
2017-04-01 – 2020-03-31
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| Keywords | マルテンサイト / 形状記憶合金 / ω相 / チタン合金 |
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| Outline of Final Research Achievements |
Effect of ω phase on pseudoelasticity in β-Ti alloys was investigated in this study. Cyclic loading-unloading tensile tests were performed at various temperatures using special alloy; volume fraction of ω phase of this alloy is not affected by deformation temperature. Stress for inducing martensite decreases as cycle number at the range of -115 ～ 120℃ increases. Stress for reverse transformation also decreases as cycle number at -115℃ increases. These results imply that shuffling magnitude of ω phase affects pseudoelasticity of β-Ti alloy. Quantitative evaluation of shuffling magnitude was attempted by pair distribution function (PDF) analysis.
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| Free Research Field |
金属組織学
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| Academic Significance and Societal Importance of the Research Achievements |
本研究ではω相のシャッフリング量が機能劣化に影響を及ぼすことが示唆されたが，シャッフリング量の決定には至らず，ω相のシャッフリング量と機能劣化を直接結び付けるには至らなかった．しかし，結晶の局所構造を加熱その場環境下で解析可能な結晶PDF解析は，形状記憶・超弾性合金の研究において今後強力なツールになることが期待される．本研究は結晶PDF解析を金属材料に適用した数少ない事例であり，学術的に意義があると言える．
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