| Project/Area Number |
26420021
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Multi-year Fund |
|---|
| Section | 一般 |
|---|
| Research Field |
Materials/Mechanics of materials
|
|---|
| Research Institution | Oita University |
|---|
Principal Investigator |
|
|---|
| Research Collaborator |
HAN SEUNGZEON 韓国材料科学研究院, 主任研究員
|
|---|
| Project Period (FY) |
2014-04-01 – 2017-03-31
|
| Project Status |
Completed (Fiscal Year 2016)
|
| Budget Amount *help |
¥5,070,000 (Direct Cost: ¥3,900,000、Indirect Cost: ¥1,170,000)
Fiscal Year 2016: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2015: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2014: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
|
|---|
| Keywords | 超微細粒 / 疲労 / き裂 / 強変形加工 / 微視組織 / 銅 / 微細結晶粒 / 応力拡大係数 / 結晶粒微細化 / 疲労き裂 / すべり帯 / 動的再結晶 |
|---|
| 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.
|
