| Project/Area Number |
25630014
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Multi-year Fund |
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| Research Field |
Materials/Mechanics of materials
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| Research Institution | Kobe University |
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Principal Investigator |
Nakai Yoshikazu 神戸大学, 工学(系)研究科(研究院), 教授 (90155656)
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| Project Period (FY) |
2013-04-01 – 2016-03-31
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| Project Status |
Completed (Fiscal Year 2015)
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| Budget Amount *help |
¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
Fiscal Year 2015: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2014: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2013: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
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| Keywords | 薄膜 / ナノ結晶 / 環境強度 / 疲労 / ナノ結晶材料 / 疲労強度 / 疲労き裂伝ぱ / Hall-Petchの関係 |
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| Outline of Final Research Achievements |
In the present project, the effect of grain size on the mechanical strength of electrodeposited nickel thin film was studied. By EBSD analysis, grain boundaries in the material were found to be large twist angle boundaries. In the measurement of grain size by EBSD, the step size should be less than tenth part of grain size.
Either relation between 0.2% proof strength, tensile strength, or fatigue limit and grain size of electro deposited nickel thin film is different from that of bulk nickel plate with conventional grain size, and this difference is large for smaller grain size thin film. This is considered to come from the fact that grain boundary has area with volume, not a face with no thickness. For the consideration of Hall-Petch relationship, mean free path of dislocation should be considered, that is actual grain size minus grain boundary area size.
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