2011 Fiscal Year Final Research Report
Interface integrity based on the control of strain-induced anisotropic diffusion
| Project/Area Number |
22656028
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Single-year Grants |
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| Research Field |
Materials/Mechanics of materials
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| Research Institution | Tohoku University |
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Principal Investigator |
MIURA Hideo 東北大学, 大学院・工学研究科, 教授 (90361112)
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| Co-Investigator(Kenkyū-buntansha) |
SUZUKI Ken 東北大学, 大学院・工学研究科, 助教 (40396461)
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| Project Period (FY) |
2010 – 2011
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| Keywords | 材料設計 / プロセス / 物性 / 評価 / 機械材料 / 界面 / 健全性 |
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| Research Abstract |
The degradation mechanism of Ni-base superalloy under an uni-axial strain at high temperature was analyzed by molecular dynamics (MD)analysis. The strain-induced anisotropic diffusion of Al atoms perpendicular to the interface between finely dispersed .' (Ni3Al)phase and . phase (Ni matrix)was observed clearly in a Ni(001)/Ni3Al(001)interface structure. It was found that Al, Co, Cu, W, and Ti atoms accelerated the rafting. On the other hand, Ta, Pd, Zr, Mo, and Mg atoms were found to suppress the rafting. The estimated results were validated by experiments using thin-film stacked structures. The 0. 2%tensile strain was applied parallel to the interface during the annealing of the stacked structure by using a four-point bending method. It was confirmed that the diffusion of atoms perpendicular to the interface was accelerated drastically. It was also confirmed that titanium and tungsten atoms which are already doped in the alloy accelerated this phenomenon seriously. On the other hand, the addition of palladium and tantalum was found to be effective for suppressing the diffusion of Al atoms around the interface. Therefore, the application of MD analysis to the design of a novel heat resistant material is very effective for improving the efficiency of energy power plants for next generation.
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