1995 Fiscal Year Final Research Report Summary
A New Alloy Design Method utilizing Diffusion Induced Recrystallization
| Project/Area Number |
06650721
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Physical properties of metals
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
KAJIHARA Masanori Tokyo Institute of Technology, Department of Materials Science and Engineering, Associate Professor, 大学院・総合理工学研究科, 助教授 (10161035)
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| Co-Investigator(Kenkyū-buntansha) |
KATO Masaharu Tokyo Institute of Technology, Department of Materials Science and Engineering,, 大学院・総合理工学研究科, 教授 (50161120)
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| Project Period (FY) |
1994 – 1995
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| Keywords | Diffusion Induced Recrystallization / Diffusion Controlled Grain Boundary Migration / Fe-Cu Binary System / Dissolution Reaction / Interdiffusion |
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| Research Abstract |
Diffusion induced recrystallization (DIR) in the Fe (Cu) system was experimentally studied using Cu/ (Fe-4.8Cu) /Cu diffusion couples in order to develop a new alloy design method based on a fast diffusion phenomenon duc to DIR.Cu/ (Fe-4.8Cu) /Cu diffusion couples, which consist of pure copper single crystals and an Fe-4.8Cu polycrystalline specimen, were anecaled at 1323K for various times between 300 and 86400s. At this annealing temperature, DIR occurs in the Fe-Cu phase from the interface of the diffusion couple and grows with increasing annealing time according to the relation l=1.6 (t/t_0) ^<0.29>, where l is the thickness of the DIR region in mum, t the annealing time in s and t_0 the unit time (1s). On the other hand, the thickness w of the Fe-Cu phase decreases with increasing annealing time according to the relation w/w_0=1-5.0*10^<-5>* (t/t_0) ^<0.5>, where w_0 stands for the initial thickness of the Fe-Cu phase. Thus, the Fe-Cu phase will be completely occupied with DIR regions at an annealing time of 56h.
The observations were numerically analyzed utilizing a energy balance model proposed by one of the present authors. This model gives a quantitative relationship between the driving force for DIR and the migration rate of the moving grain boundary. For the analysis, the grain boundary diffusion of copper along the grain boundaries of DIR regions is the rate controlling process and the Fe-Cu phase is thermodynamically ideal. The equation l=1.04 (t/t_0) ^<1/3> has been obtained to describe the kinetics of DIR in the Fe-Cu phase under the present experimental conditions. The analysis quantitatively accounts for the observations.
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Research Products
(4 results)
