Li_2O-Al_2O_3-SiO_2-B_2O_3系统玻璃纤维的核化晶化机理

MECHANISM OF NUCLEATION AND CRYSTAL-LIZATION OF Li_2O-Al_2O_3-SiO_2-B_2O_3 SYSTEM GLASS FIBER

本文运用扫描电镜、X射线衍射定性分析和定量分析等手段,研究了以TiO_2为成核剂的Li_2O-Al_2O_3-SiO_2-B_2O_3系统玻璃纤维的核化晶化机理。结果表明,不加TiO_2时,纤维析晶与同成份的块状玻璃明显不同,而且析晶具有明显的方向性。添加TiO_2后,整个纤维内部均匀析晶。另外,TiO_2的加入降低了高温粘度,升高了低温粘度,加快了析晶速度,并促使β-锂霞石(Li_2O·Al_2O_3·2SiO_2)较快地向β-锂辉石(Li_2O·Al_2O_3·4SiO_2)转变。

Mechanism of nucleation and crystallization of Li_2O-Al_2O_3-SiO_2-B_2O_3 system glass fiber was studied by SEM and XRD. The results show that: without nucleating agent TiO_2, the crystallization rate of glass fiber is much faster than that of bulk glass of the same composition and oriented crystals will be observed in the fiber. When TiO_2 is added, glass fiber crystallizes uniformly. On the other hand, the addition of TiO_2 results in an increase of viscosity at low temperature but a decrease at high temperature. Also, the crystallization rate of fiber is increased by TiO_2, which results in a faster transformation from β-eucryptite to β-spodumene.