B_2O_3对CaO-MgO-Al_2O_3-SiO_2体系玻璃的结构和析晶性能的影响

Effects of B_2O_3 Addition on Structure and Crystallization Ability of CaO-MgO-Al_2O_3-SiO_2 Glass Sintering Aids

采用溶胶-燃烧法制备了CaO-MgO-Al_2O_3-SiO_2体系玻璃的粉体,粉体的颗粒细小均匀,其平均颗粒粒径在80 nm左右。采用X射线衍射分析、傅里叶变换红外光谱分析、差热分析等方法研究了玻璃粉体样品的结构和析晶性能。研究结果表明,加入B_2O_3后,样品中形成由[SiO_4]四面体网络和[BO_3]三角体链共同构成的结构骨架,使玻璃结构更加紧密,并增强了阴离子结构基团与Ca^(2+)、Mg^(2+)等网络外体离子之间的静电作用;B_2O_3的加入显著降低了样品的玻璃转变温度,明显抑制CaOMgO-Al_2O_3-SiO_2玻璃体系的析晶能力,经过1150℃热处理后的样品基本保持非晶态结构。

The powders of CaO-MgO-Al2O3-B2O3-SiO2 system glass with varied B2O3 content were prepared by a sol-combustion method. The resulted powders exhibited an amorphous nature and uniform particle morphology,with the mean particle sizes around 80 nm. The structure and crystallization behavior of the powders were investigated as a function of B2O3 content by employing XRD,FT-IR and DTA methods. The addition of B2O3 led to coexistence of [SiO4] tetrahedral network and [BO3] triangle chains as the structural frameworks,producing a tighter glass structure while enhancing static electric interactions between the anion structural units and network-modifying cations such as Ca^2＋ and Mg^2＋. As a result,the transition temperature Tg of the glass system was significantly decreased due to the addition of B2O3. Meanwhile,the crystallization ability of the glass powders at elevated temperatures was effectively suppressed. The borosilicate glass powders basically maintained an amorphous structure after calcining at 1150 ℃.