2002 Fiscal Year Final Research Report Summary
Development of new heat-resistant structural composite materials by MGC bulk and fiber crystals
| Project/Area Number |
12555205
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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 | 展開研究 |
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| Research Field |
Metal making engineering
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| Research Institution | Tohoku University |
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Principal Investigator |
YOSHIKAWA Akira Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Research Associate, 多元物質科学研究所, 助手 (50292264)
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| Co-Investigator(Kenkyū-buntansha) |
WAKU Yoshikaru Ube Industries Ltd., Chief researcher, 主任研究員
KO Jung Min Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Research Associate, 多元物質科学研究所, 助手 (00333881)
FUKUDA Tsuguo Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Guest Professor, 多元物質科学研究所, 客員教授 (30199236)
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| Project Period (FY) |
2000 – 2002
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| Keywords | Eutectics / micro-Pulling-Down method / Structural material / Single crystal / saving energy |
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| Research Abstract |
In this study, we investigated Melt Growth Composite (MGC) materials which can be used as structural materials at high temperature region around 1500℃ in air atmosphere. We established crystal growth method of MGC materials. We applied shape-control technique and achieved to fabricate fiber, plate and rod-shaped MGC materials. We studied several systems of MGC crystals and discovered highest strength in Y_3Al_5O_<12>(YAG)/AL_2O_3(sapphire)/ZrO_2(zirconia) ternary system.
1. Establishment of crystal growth method of MGC materials
To develop a thermally stable reinforcement materials which can be used at 1700℃, we investigated the conditions for stable growth of high quality, homogeneous eutectics crystals with controlled microstructure. By modifying the micro-pulling-down method with crucible, hot zone etc., we have established a new crystal growth technique for the eutectic crystals. We have clarified the relative orientations and method to control the microstructure of the eutectic comp
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onents of YAG and sapphire, by TEM electron diffraction analysis.
2. Shaped crystal growth
The meniscus was well controlled by the end shape of the crucible, and we found a strong relation between meniscus and shape of grown crystals. Based on this observation, we achieved growing bulk eutectic crystals up to 5mmφ in diameter, plate crystals up to 10mm width, fiber crystals around 150μm in diameter. This crystal shape control technique can be applied for various field of related industry.
3. Strength in high temperature
We investigated several eutectic systems to search for the material which has higher strength than sapphire/YAG binary system. Among these, sapphire/YAG/zirconia ternary system showed highest strength. We tested tensile strength at room temperature in air atmosphere and at 1500℃ in Ar, and measured fundamental physical properties of the grown crystals such as thermal expansion coefficient etc. Tensile strengths reached 1730MPa at room temperature and 970MPa at 1200℃ in Ar atmosphere which is highest value in the world. Less
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Research Products
(20 results)
