2016 Fiscal Year Final Research Report
Study on the microstructure and high-cycle fatigue property of ultrafine grained copper processed by severe plastic deformation
| Project/Area Number |
26420021
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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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 |
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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) |
2014-04-01 – 2017-03-31
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| Keywords | 超微細粒 / 疲労 / き裂 / 強変形加工 / 微視組織 / 銅 |
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| Outline of Final Research Achievements |
It was shown that, using the partial-notched specimen, specification of the initiation site of the fatal natural crack could be achieved despite the microstructural inhomogeneity resulting from ECAP. Although the crack growth paths inclined 45° and 90° to the loading-axis were observed in the different locations on the surface, crack faces in these cracks were extended along one set of maximum shear stress planes, corresponding to the final ECAP shear plane. To investigate the physical background of the unique crack growth directions of UFG Cu, the SIF values were evaluated, by assuming a semi-infinite body with inclined semi-elliptical surface cracks, subjected to tension stress in the x-direction at infinity. The shape of the crack faces/paths was strongly affected by the in-plane shear-mode deformation. The role of microstructure on the crack initiation/growth was clarified from the fatigue tests of precipitate-strengthened Cu-6Ni-1.5Si alloy.
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| Free Research Field |
材料力学
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