Solid Solution of Zr into Anhydrous Al2(SO4)3 Crystal Lattice and [eta]->[alpha] Phase Transformation of Al2O3 Formed by Thermal
More than 60mol% Zr4+ ion (ZrO2/(Al2O3+ZrO2)) is soluble into anhydrous Al2(SO4)3 crystal lattice. The apparent crystallite size decreases with increasing Zr4+ content, and the thermal decomposition temperature reduces at contents of zirconia >20mol%. Alumina/zirconia composite powders, in which...
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Veröffentlicht in: | Journal of the Ceramic Society of Japan 1999-01, Vol.107 (1241), p.41 |
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Hauptverfasser: | , , , , |
Format: | Artikel |
Sprache: | eng |
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Zusammenfassung: | More than 60mol% Zr4+ ion (ZrO2/(Al2O3+ZrO2)) is soluble into anhydrous Al2(SO4)3 crystal lattice. The apparent crystallite size decreases with increasing Zr4+ content, and the thermal decomposition temperature reduces at contents of zirconia >20mol%. Alumina/zirconia composite powders, in which an amorphous zirconia phase is dispersed in a matrix of fine η-alumina particles, are obtained by thermal decomposition of the sulfate solid solution. Tetragonal phase of zirconia crystallizes at 1100°C and the crystallinity increases with increasing the temperature of the heat-treatment. When mono-dispersed ultra fine particles of zirconia are added to η-alumina formed by thermal decomposition of pure anhydrous aluminum sulfate, the η->α phase transformation of alumina is suppressed, and the effect increases with increasing the amount of the additive. On the contrary, a small quantity of ZrO2α phase transformation of alumina is accelerated. The acceleration effect becomes larger with increasing the content of ZrO2. |
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ISSN: | 1882-0743 1348-6535 |