| Project/Area Number |
12450300
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Metal making engineering
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
OHSASA Ken-ichi Hokkaido Univ., Grad. School of Eng., Asso. Prof., 大学院・工学研究科, 助教授 (90111153)
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| Co-Investigator(Kenkyū-buntansha) |
HAYASHI Shigenari Hokkaido Univ., Grad. School of Eng., Inst., 大学院・工学研究科, 助手 (10321960)
MATSUURA Kiyotaka Hokkaido Univ, Grad. School of Eng., Inst., 大学院・工学研究科, 助手 (60142692)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥10,600,000 (Direct Cost: ¥10,600,000)
Fiscal Year 2001: ¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 2000: ¥8,000,000 (Direct Cost: ¥8,000,000)
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| Keywords | prediction of casting structure / solidification and casting / aluminum base alloy / heterogeneous nucleation / columnar-equiaxed transition / database / enthalpy method / 熱伝達係数 |
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| Research Abstract |
In order to construct the database of alloys for the prediction of casting structure, Items and methods that are required for the construction were investigated. The heterogeneous nucleation parameters for aluminum base alloys were evaluated.
1) Evaluation of heterogeneous nucleation frequency distribution
In order to select the nucleation model for the database, sample alloys such as pure Al, Al-Cu, Al-Si, Al-Fe, Al-Ti were melted and dispersed by stirring in K_2S0_4-Li_2SO_4 molten salt Each dispersed particle of alloys was re-melted and its melting point was measured in the K_2SO_4-Li_2SO_4 molten salt. As the result, the nucleation frequency of each particle increased with increasing undercooling, but decreased at the highest undercooling. It was confirmed that a simple power form with respect to undercooling for the expression of heterogeneous nucleation was adopted for conventional casting condition.
2) Heat transfer analysis for a multi-component alloy by using thermodynamic calcul
… More
ation
In the present study, the nucleation parameters of alloys were evaluated by comparing experimentally obtained structures and simulated ones. In order to carry out the simulation for the structure formation of a multi-component alloy, precise heat transfer calculation is needed to produce the same temperature field with the casting obtained by the experiment. In order to simulate the heat transfer process during the solidification of a multi-component alloy, a new method was developed based on the enthalpy method by using a thermodynamic calculation.
3) Evaluation of nucleation parameter for aluminum alloys
Unidirectional solidification experiment of aluminum base binary and commercial alloys were carried out. Experimentally observed locations of columnar to equiaxed transition (CET) were simulated by a method based on the Monte Carlo procedure, and nucleation parameters were determined by producing the locations of CET for each sample. The nucleation parameters, which are expressed as a power with respect to undercooling, increased with increasing silicon content for both binary and commercial aluminum base alloys.
It is expected that the structure of more large or complicated casting can be predicted by using above parameters which can be evaluated by a laboratory scale experiment. Less
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