SiO2-Al2O3-K2O-Na2O系ガラスにおける白榴石の生成と熱膨脹
SiO2-Al2O3-K2O-Na2O系ガラスにおける白榴石の生成と熱膨脹
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SiO2-Al2O3-K2O-Na2O 玻璃中白榴石的形成和热膨胀
DOI：
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发表时间：
1972
期刊：
影响因子：
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通讯作者：
三郎 赤木
中科院分区：
文献类型：
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作者：
武 星川;三郎 赤木
通过测定重烧后白榴石的析出量和重烧玻璃、析出白榴石晶体的热膨胀系数以及重加热样品中残留玻璃基质组成的玻璃的热膨胀系数，研究了重烧后SiO_2-Al_2O_3-K_2O-Na_2O玻璃的热膨胀与白榴石晶体的形成。结果表明：1)在700℃~1200℃的温度范围内，玻璃中有白榴石析出，玻璃中的白榴石析出量随加热温度的降低而增加，玻璃成分接近理论白榴石组成时，玻璃中白榴石的析出量也随之增加；3)玻璃中析出的白榴石晶体在400℃以下的热膨胀系数为α=-15.5×10-6/°C(平行于c轴)，α⊥=39.5×10-6/°C(垂直于c轴)和(α_？+2α⊥)/3=21.7×10-6/°C(平均值)。重新加热玻璃的异常高膨胀归因于高膨胀的白榴石晶体。
Thermal expansion of reheated SiO2-Al2O3-K2O-Na2O glasses has been related to the formation of leucite crystals in them by determining the amount of leucite precipitated upon reheating and the thermal expansion coefficients of reheated glassses, leucite crystal precipitated in the glass and glass of the composition corresponding to residual glassy matrix in the reheated samples. The following results were obtained.1) Leucite crystals were precipitated in glasses upon reheating them at 700°-1200°C. The amount of leucite crystals precipitated in glasses increased as the temperature of reheating was lowered and the composition of glass approached the theoretical leucite composition.2) The linear thermal expansion coefficient measured below 400°C of the reheated glass increased linearly with increasing amount of leucite crystals precipitated in the glass, changing from 10.7×10-6 to 17.8×10-6/°C for 0 to 47wt% leucite.3) The thermal expansion coefficient below 400°C of leucite crystals precipitated in the glass was α_??_=-15.5×10-6/°C (parallel to the c-axis), α⊥=39.5×10-6/°C (perpendicular to the c-axis) and (α_??_+2α⊥)/3=21.7×10-6/°C (average).4) The thermal expansion of the reheated glass was given as the sum of those of leucite crystals and residual glass, and the anomalously high expansion of the reheated glasses was attributed to the high expansion leucite crystals.