2010 Fiscal Year Final Research Report
Study on the application of ultrafine grained copper to electric materials.
| Project/Area Number |
20560080
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Materials/Mechanics of materials
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| Research Institution | Oita University |
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Principal Investigator |
GOTO Masahiro Oita University, 工学部, 教授 (30170468)
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| Research Collaborator |
HAN Seungzeon 韓国材料科学研究院, 主任研究員
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| Project Period (FY) |
2008 – 2010
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| Keywords | 結晶粒微細化 / 銅 / 疲労 / 微小き裂 / 非平衡粒界 |
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| Research Abstract |
In the present study, the fatigue tests of UFG copper processed by ECAP were conducted to clarify the fatigue mechanism. The experimental analysis was made and the fatigue crack initiation behavior, the relationship between the change in surface hardness and fatigue damage due to stressing, the crack growth behavior and growth mechanism, and the growth law of small surface-cracks which control the fatigue life of smooth specimens, were clarified. In addition, post-ECAP annealing was conducted to improve the fatigue strength in a long-life field because that the less improvement of fatigue strength in long life fields resulted from instability of microstructure with non-equilibrium grain boundaries. Results of copper (99.9%Cu) with post-ECAP annealing at 180℃ showed the enhanced fatigue strength at 2x10^7 cycles (about 1.4 times of as-ECAPed copper with 99.99%Cu).
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