| Project/Area Number |
26420748
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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 |
Material processing/Microstructural control engineering
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| Research Institution | Doshisha University |
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Principal Investigator |
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| Project Period (FY) |
2014-04-01 – 2017-03-31
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| Project Status |
Completed (Fiscal Year 2016)
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| Budget Amount *help |
¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000)
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: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
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| Keywords | Grain boundary / SCC / Non-equilibrium GB / 強ひずみ加工法 / 超微細結晶粒 / 応力腐食割れ / 超微細結晶材料 / 結晶粒界 / 粒界腐食 / 強ひずみ加工 / 粒界エネルギー / 腐食 |
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| Outline of Final Research Achievements |
In this work, the effect of grain size in the sub-micron range on the SCC of Cu-10wt%Zn alloys is investigated using constant load tests in ammonia vapor. The grain size is systematically controlled from 0.12 μm to 40 μm by either cold-rolling or ECAP, followed by annealing. The specimens are kept in tension until fracture under a constant stress ammonia vapor.
The time to fracture has increased with decreasing grain size reaching 1 μm, but decrease with further decreasing grain size into the sub-micron range. In other words, there is a critical grain size that the susceptibility to SCC changes. Sensitivity to IGSCC is associated with GB energy. Non-equilibrium GB have higher GB energy than equilibrium GB because they contain extrinsic dislocation in grains induced by severe plastic deformation (SPD) process, and possibly exhibit GB sliding. This inverse trend in the sub-micron range is discussed in terms of a SPD-induced ultrafine grain (UFG) microstructure
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