書誌事項
- タイトル別名
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- Studies on the Co-precipitates of Alumina and Silica Gels and its Transformations at Higher Temperatures
- アルミナ-シリカケイ ニ カンスル ケンキュウ 1
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説明
The system Al2O3-SiO2 is studied using co-precipitated gels with pH values in the range 5.0-8.0, obtained by the addition of urea to alcohol solution of mixed siliconethylester and aluminiumethylester.<br>Following the combustion of urea between 500°-600°C, the system appears to be amorphous up to about 1000°C. At this temperature an exothermic reaction occurs and a spinel-type phase is formed. It has various amounts of Si4+ substituted with Al3+ in the position of four co-ordination and its lattice parapeter increases as the Al2O3/SiO2 ratio increases.<br>Mullite is formed at higher temperatures by the thermal decomposition of the spineltype phase. In the temperature range 1000°-1200°C mullite exhibits two-dimensional grain growth. The exothermic peak of the DTA-curve at about 1200°C is related to the velocity of formation of mullite and at temperatures higher than 1200°C mullite shows a remarkable grain growth. Chemical composition of mullite is not always constant and the possible existence of mullite containing more silica than 3:2 is suggested without saying the existence of the ratio Al2O3/SiO2=3/2-2/1. According to the electron-microscopic studies mullite showed always a needlelike morphology irrespective of the mode of formation.<br>It is suggested from the measurement of the lattice spacing that the cristobalite formed in the silica-rich gel has some solid solution of alumina and is different from that produced from silica ge lalone.
収録刊行物
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- 窯業協會誌
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窯業協會誌 70 (795), 87-93, 1962
公益社団法人 日本セラミックス協会
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詳細情報 詳細情報について
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- CRID
- 1390282680225267712
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- NII論文ID
- 110002302426
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- NII書誌ID
- AN00245650
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- ISSN
- 18842127
- 00090255
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- NDL書誌ID
- 9214805
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- 本文言語コード
- ja
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- データソース種別
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- JaLC
- NDL
- Crossref
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- 抄録ライセンスフラグ
- 使用不可