Nucleation and Crystal Growth of <TEX>$beta$</TEX>-eucryptite in a Glass of the Molecular Composition Li2O.Al2O3.2SiO2

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J. Korean Ceram. Soc. > Volume 22(3); 1985 > Article

Journal of the Korean Ceramic Society 1985;22(3): 53.

Li2O.Al2O3.2SiO2의 조성을 갖는 유리에서 $beta$-eucryptite의 핵생성 및 결정성장

이상현, 장수진

서울대학교 무기재료공학과

Nucleation and Crystal Growth of $beta$-eucryptite in a Glass of the Molecular Composition Li2O.Al2O3.2SiO2

ABSTRACT

Nucleation and crystallization of $beta$-eucryptite in a glass of molecular percentage composition Li2O.Al2O3.2SiO2 are studied. The glasses are made by quenching of the melts from 143$0^{circ}C$ to room temperature. Heat-treatment for nucleation and crystal growth are caried out at various temperature in the range between 50$0^{circ}C$ and 80$0^{circ}C$ with different duration of time. The amounts of crystallization are estimated by the method of x-ray powder diffraction. As the results a time-temperature-transformation relation for crystallization is derived. The maximum rate of crystallization is observed at about 75$0^{circ}C$ from the T-T-T-curve while the crystallization temperature is detected at 67$0^{circ}C$ by DTA measurement. The crystallization temperature moved to 62$0^{circ}C$ by adding 5 weight percents of TiO2 and it moved to 78$0^{circ}C$ by adding 2 weight percents of V2O5. The crystallization temperature moved to 62$0^{circ}C$ by adding 5 weight percent of TiO2 it moved to 78$0^{circ}C$ by adding 2 weight percents of V2O5 The activation energy for crystallization from the pure glass is calculated as 68 Kcal/mol and it varied to 53 Kcal/mol and 110Kcal/mol when 5 weight percents of TiO2 and weight percents of V2O5 are added respectively.