P2O5对Li2O-SiO2-Al2O3-K2O-ZnO体系微晶玻璃析晶性能的影响

采用差热分析、X射线衍射及扫描电镜分析手段研究了P₂O₅对Li₂O-SiO₂-Al₂O₃-K₂O-ZnO体系牙科微晶玻璃析晶性能的影响, 并确定了P₂O₅的最适含量. 结果发现P₂O₅是该玻璃体系的有效成核剂, 未添加P₂O₅的玻璃体系成核密度低, 热处理后不能形成微晶体, 且主晶相为硅酸锂; 添加P₂O₅使玻璃在热处理后形成以二硅酸锂为主晶相的微晶玻璃. 该玻璃体系中添加4.5 wt%的P₂O₅可以得到较高体积含量和理想显微结构的牙科二硅酸锂微晶玻璃. P₂O₅含量为6 wt%的基质玻璃发生乳浊, 呈不透明的乳白色.

Effect of P2O5 Addition on the Crystallization Properties of Li2O-SiO2-Al2O3-K2O-ZnO Glass-Ceramic

Differential Thermal Analyses (DTA), X-Ray Diffraction analyses (XRD) and Scanning Electron Microscopy (SEM) were used to study the effect of P2O5 addition on the crystallization properties of dental glass-ceramics in the Li2O-SiO2-Al2O3-K2O-ZnO glass system. It was concluded that P2O5 was an effective nucleating agent for this glass system. The nucleation density of this glass system was too low to form tiny crystal after heat-treatment, when it contained no P2O5, and the major crystal phase was lithium silicate. Adding P2O5 resulted in major tiny crystal phase of lithium disilicate after heat-treatment. 4.5 wt% of P2O5 could give high content and prospecting SEM appearance of dental lithium disilicate glass-ceramic. 6.0 wt% of P2O5 opacified base glass.