2009 Fiscal Year Final Research Report
Interfacial Science of Nano-lamellar Materials
| Project/Area Number |
19206066
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Physical properties of metals
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| Research Institution | Tohoku University |
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Principal Investigator |
MARUYAMA Kouichi Tohoku University, 大学院・環境科学研究科, 教授 (90108465)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHIMI Kyosuke 東北大学, 大学院・環境科学研究科, 准教授 (80230803)
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| Project Period (FY) |
2007 – 2009
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| Keywords | チタンアルミナイド / 界面構造 / ミスフィット転位 / 降伏応力 / クリープ強度 |
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| Research Abstract |
The present research studied mechanical properties of nano-lamellar materials consisting of α_2Ti_3Al phase and γTiAl phase. This type of materials contains a large number of α_2/γ interfaces, which act as obstacles to dislocation motion and improve strength of such materials. Elastic limit of nano-lamellar materials is insensitive to lamellar thickness λ, but the interfaces without misfit dislocation provide a higher elastic limit. Work-hardening rate of nano-lamellar materials is inversely proportional to λ, and the coefficient is increased by the introduction of misfit dislocations. Disappearance of α_2/γ interfaces during high temperature exposure causes degradation of nano-lamellar materials. Bands of β_0 precipitates are formed after dissolution of α_2 lamellae when a β_0 phase forming element is added. The precipitation bands give high creep strength after the disappearance of α_2 lamellar.
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