氟对锂铝硅系统玻璃结构及析晶的影响

通过引入氟以降低锂铝硅玻璃的高温黏度,使"温度-黏度"曲线适应浮法工艺的需求,并采用激光拉曼光谱、XRD、高温旋转黏度计等测试手段研究氟对锂铝硅系统玻璃的结构及随后析晶的影响。结果表明:氟的引入使母体玻璃网络结构中的[Si(Al)O4]四面体相互之间形成的环结构向小环结构发展,[Si(Al)O4]四面体之间的相互连接程度降低,Si(Al)—O—Si(Al)键的振动减弱,从而能有效地降低母体玻璃的高温黏度。随着氟引入量从0.00mol增加到0.28mol,母体玻璃在晶化过程中析出的主晶相并未发生改变,皆为β-锂辉石固溶体,且析出的主晶相含量随氟引入量的增加而增加。此外,结合Raman光谱分析可以发现,试样中有微量的锐钛矿晶相析出。

Effect of Fluorine on Structure and Crystallization of Lithium Aluminosilicate Glasses

The fluorine was introduced to the lithium aluminosilicate glasses for decreasing viscosity and melting temperature for float process.The influence on the structure and crystallization of lithium aluminosilicate glasses with various fluorine dopants was investigated by means of Raman spectroscopy, XRD and high temperature viscosity test.The results showed that the addition of fluorine induced the average Si(Al)O_4 ring structures shifted progressively to smaller rings and the degree of connection of Si(Al)O_4 tetrahedron was decreased in the three-dimensional glass network.The viscosity of initial glasses was effectively decreased with fluorine dopants.When the addition of fluorine increased from 0.00mol to 0.28mol, the crystallinity of specimens was increased but the main phase was still β-spodumene.Moreover, the Raman spectra showed that the anatase precipitated as minor phase after heat-treated.