1990 Fiscal Year Final Research Report Summary
The Diffusion Process of Hydrogen in the Quasi-Periodic Structure
| Project/Area Number |
63550471
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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 | Ibaraki University |
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Principal Investigator |
ICHIMURA Minoru Ibaraki Univ., Fac. of Engin., Associate Professor, 工学部, 助教授 (20007636)
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| Co-Investigator(Kenkyū-buntansha) |
SASAJIMA Yasushi Ibaraki Univ., Fac. of Engin., Associate Researcher, 工学部, 助手 (80187137)
IMABAYASHI Mamoru Ibaraki Univ., Fac. of Engin., Professor, 工学部, 教授 (10007601)
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| Project Period (FY) |
1988 – 1990
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| Keywords | Quasicrystal / Diffusivity of Hydrogen / Solubility of Hydrogen / Vacuum extraction method / Monte-Carlo Method / Fibonacci lattice / Penrose pattern / Tracer atom |
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| Research Abstract |
Al - Cu - Fe quasicrystal was produced by the conventional casting method. The diffusivity and solubility of hydrogen of the obtained samples were measured. In addition to the real experiments, the computer experiments of the diffusion process on the 2 dimensional Fibonacci and 2 dimensional Penros e lattices were performed. The diffusivity of the tracer atoms was calculated by the Monte-Carlo method and the diffusion properties peculiar to the quasi-periodic structure was discussed.
We obtained the following conclusion about the diffusivity of hydrogen of the Al - Fe - Cu quasicrystal.
(1) Al_<65>Cu_<20>Fe_<15> quasicrystal produced in the rare gas atmosphere contained less defects than that produced in vacuum.
(2) The diffusivity of this quasicrystal took much lower value than that of pure aluminum, copper and iron in 300 - 600.
(3) The higher concentration of the quasicrystal phase in the sample, lower the diffusivity of hydrogen.
(4) The solubility of hydrogen at 600 was larger if the concentration of the quasicrystal phase was higher.
Concerning the diffusion process on the Fibonacci lattice, we found that the diffusivity of the tracer atoms were much lower than that of the random alloy phase. From the Monte-Carlo simulation of the diffusivity on the 2 dimensional Penrose lattice, We found that the effects of the quasi-periodic network was not so strong than that of the quasi-periodic potential sequence.
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