2013 Fiscal Year Final Research Report
Materials science and engineering of hydrogen-induced shear transformation in hydrogen absorbing materials
| Project/Area Number |
25630304
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Single-year Grants |
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| Research Field |
Structural/Functional materials
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| Research Institution | Kyoto University |
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Principal Investigator |
INUI Haruyuki 京都大学, 工学(系)研究科(研究院), 教授 (30213135)
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| Project Period (FY) |
2013-04-01 – 2014-03-31
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| Keywords | 協調的原子集団励起 / プラストン / 変形双晶 / 核生成 / 臨界体積 / マイクロピラー / 試験片サイズ依存性 / c/a軸比 |
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| Research Abstract |
The activation of deformation twinning is indispensable to promote the workability of Mg and its alloys, but their activation has not been well understood. The activation of deformation twinning is known to be difficult when the grain size is reduced down to the orders of nano-meters. On the assumption of the existence of critical volume for twin nucleation, we have investigated nucleus sizes for deformation twinning through the determination of the critical volume for the transition in deformation modes from twinning to slip. When single crystals of Mg of the size of micron-meter order are compressed along the a-axis direction, twinning on {11-21} is observed. If the specimen size is further reduced down to sub-micron orders, slip on {11-23} id observed to operate instead of twinning on {11-21}. The similar behavior is observed in LPSO single crystals of the Mg-Zn-Y system. The critical volume for twinning in these alloys is thus determined to be about 1 micrometer.
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