| Project/Area Number |
60470063
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
金属材料(含表面処理・腐食防食)
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| Research Institution | Tohoku University
The University of Tokyo |
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Principal Investigator |
SAKUMA Taketo Professor, Dept. of Materials Science,, 工学部, 教授 (50005500)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 1985: ¥3,700,000 (Direct Cost: ¥3,700,000)
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| Keywords | partially stabilized zirconia / fracture toughness / martensitic transformation / spinodal decomposition |
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| Research Abstract |
Microstructure and mechanical properties of arc-melted zirconia alloys were examined. The results obtained are as follows;
1. Microstructure markedly changes with the amount of cubic stabilizing oxides such as yttria and celia.
2. The diffusionless c-t transition in <ZrO_2> - <Y_2O_3> alloys has a nature of second order phase transition, which is characterized by an unique microstructural change.
3. The herring-bone structure is developed in <ZrO_2> - <Y_2O_3> alloys with yttria content around 3 mol%.
4. The modulated structure is formed during isothermal aging in the cubictetragonal two phase region in <ZrO_2> - <Y_2O_3> alloys. The structure seems to be related to the metastable phase separation induced by spinodal decomposition.
5. The composition and microstructural control is particularly important to improve the fracture toughness of partially stabilized zirconia. The optimum composition for attaining the highest fracture toughness was determined in <ZrO_2> - <Y_2O_3> and <ZrO_2> - <CeO_2> alloys.
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