不同粉体粒度对二硅酸锂玻璃陶瓷热压铸前后微观结构和性能的影响

摘要

分析了不同粒度对Li2O-SiO2-K2O-Al2O3-ZrO2-P2O5系新型齿科二硅酸锂玻璃陶瓷在热压铸前后微观结构和性能的影响。分别用差热分析（DTA）、扫描电镜（SEM）和x射线衍射（XRD）分析了玻璃陶瓷的晶化温度、微观结构和物相组成。根据ISO6872标准测试材料的弯曲强度。结果显示,不同粉体粒度的玻璃陶瓷间微观形貌有明显差异;不同的粉体粒度和热压铸工艺对玻璃陶瓷的晶相组成无显著影响;不同粉体粒度的玻璃陶瓷在热压铸前后强度均有差异,热压铸后,各组弯曲强度显著提高,但是粒度的变化和强度之间无明确的相关性。结果表明,不同粒度对实验玻璃陶瓷的晶化行为和性能都有显著影响。%The purpose of this study was to investigate the effects of grain size on the microstructure and proper- ties of a novel lithium disilicate glass-ceramic located in Li2O-SiO2-K2O-Al2O3-ZrO2-P2O5 system, before and after heat pressing treatment. The crystalline phase composition, crystallization temperature and microstructures were analyzed by X-ray diffractometry (XRD), differential thermal analysis (DTA) and scanning electron microscopy (SEM). Three-point flexural strength of glass-ceramic specimens was measured following the instruction of ISO 6872. The results showed grain size and dental heat-pressing had no influence on the crystalline composition. Li2Si2O5 represented the main crystalline phase before or after heat-pressing technique. The SEM examination indicated the microstructure of specimens among groups with different grain size was different. Grain size had statically influence on flexural strength of glass-ceramics before or after heat pressing. Also, af- ter pressing, crystals aligned along the direction of pressing and glass-ceramics showed higher mechanical strength than these before heat pressing. It was concluded that grain size has a significant effect on the sintering behavior and mechanical properties of the experimental glass-ceramics both before and after heat pressing.