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Journal of the Korean Ceramic Society 1988;25(5): 541. |
| Sol-Gel법에 의한 Li2O-Al2O3-SiO2계 괴상겔 및 결정화유리의 합성 |
| 양중식, 작화제부1 |
경희대학교
1동부대학 |
| Synthesis of Monolithic Gel to Bulk glass-Ceramic in Multicomponent Li2O-Al2O3-SiO2 System |
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| ABSTRACT |
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The purpose of this investigation was to prepare multicomponent monolithic Li-Al-Si gels of composition(mol%) 16.67 Li2O-16.67 Al2O3-66.67 SiO2 and to convert the gels to monolithic glass-ceramic at low temperature without melting. The hydrolysis, DTA, TGA, TMA, SEM, pore distribution, density and the activation energy for crystallization of the glass-ceramic formation with rawmaterials of which tetraethl orhosilicate of networkforming cation(Si) is partially hydrolyzed, aluminum isoproxide and lithium methoxide prepared by Li-metal react with methanol were studied. The results were as follows : 1) Monolithic gels which were added with additional water, resulting in a total water content 2.5 to 3.0 times the stoichiometric amount required to fully hydrolyze the alkoxides. 2) Specimens were dried to form crylinders 60mm in length and 40mm in diameter in about 800 hrs at 5$0^{circ}C$. 3) $beta$-eucryptite crystals and $beta$-spodumene crystals were detected in samples heated above 75$0^{circ}C$. 4) Within the temperature and range of 25-50$0^{circ}C$ and 1,00$0^{circ}C$ the thermal expansion coefficient for crystallized samples were shown as 2.6-5.7$times$10-7/$^{circ}C$ and 7.4-12.5$times$10-7/$^{circ}C$, respectively. 5) The activation energy for the crystal growth was 11.01kcal/mol at 794$^{circ}C$ to 85$0^{circ}C$. |
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