磷硅酸盐玻璃流变性能研究

Research on Rheological Properties of Phospho-silicate Glasses

以石英砂、长石、磷灰石等原料制备了含磷的无氟硅酸盐乳浊玻璃,利用Cp、XRD和粘度等测试手段研究了熔体的流变性能。结果表明:P2O5含量增加,玻璃转变温度和假想温度变化不大,而熔体粘滞流动活化能增大,而且当P2O5含量为3mol%时,熔体会在1 522 K发生析晶。保持NBO/T值不变,MgO逐渐取代部分CaO有助于增强乳浊程度并降低熔体析晶温度,同时熔体脆性指数减小而高温粘滞流动活化能增大。这些研究成果对无氟硅酸盐乳浊玻璃的实际生产有很好的指导意义。

Fluorine-free opaque silicate glasses were prepared by conventional melt quenching method,utilizing silica,feldspar,apatite as raw materials.The rheological properties were studied by using Cp,XRD and viscosity measurements. The results show that P2O5 content has little influence on glass transition and fictive temperature,but great effect on the appearance and rheological properties.Increasing P2O5 content leads to an increase of viscous flow activation energy,and even crystallization takes place at 1 522 K in the composition with 3mol% P2O5.Keeping the constant NBO/T value,the substitution of MgO for partial CaO leads to increase of opalescent effect and decrease of crystallization temperature of melts.Accordingly,fragility index decreases and viscous flow activation energy in the high temperature range increases.This study will be instructive for the manufacture of Fluorine-free opaque silicate glasses.