2013 Fiscal Year Final Research Report
Preparation of Giant Pseudo-Single Crystals of Superelastic Alloys and the Mechanism of Grain Growth
| Project/Area Number |
24656426
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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 |
Material processing/treatments
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| Research Institution | Tohoku University |
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Principal Investigator |
ISHIDA Kiyohito 東北大学, 工学(系)研究科(研究院), 名誉教授 (20151368)
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| Co-Investigator(Kenkyū-buntansha) |
OHNUMA Ikuo 東北大学, 大学院工学研究科, 准教授 (20250714)
OMORI Toshihiro 東北大学, 大学院工学研究科, 助教 (60451530)
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| Project Period (FY) |
2012-04-01 – 2014-03-31
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| Keywords | 結晶粒成長 / Cu基形状記憶合金 / 熱処理 / 異常粒成長 / 繰り返し熱処理 / 亜結晶粒 |
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| Research Abstract |
The grain growth of beta(bcc) phase in Cu-Al-Mn base shape memory alloys has been studied. The abnormal grain growth was realized when the Cu-Al-Mn alloys were first quenched from the beta single-phase region at high temperature round 1173K and then was slowly cooled at about 773K, and subsequent heating to the beta single-region. The pseudo-single crystals due to abnormal grain growth were obtained by thermally cycling where beta phase leads to a precipitation and subsequent dissolution of the alpha phase. This abnormal grain growth phenomenon results from the formation of subgrain structure introduced through phase transformation, where the subgrain-boundary energy might be one of the driving force. These findings provide a method of fabricating a single-crystal or large-grain structure important for superelastic properties.
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