利用等静压技术制备牙科Al_2O_3/ZrO_2陶瓷材料

Preparing of Al_2O3_/ZrO_2 Composite Dental Ceramics through Isostatic Pressing Technology

目的利用等静压技术制备高密度坯体,减少牙科陶瓷烧结时的尺寸收缩。方法制备Al2O3/ZrO2复合粉体,采用先干压预成型,再等静压压实的两步成型法压制素坯,在1400℃下烧结,保温不同时间(2h、3h、4h),测量材料的密度、强度和微观结构,观察材料的烧结性能。结果随着保温时间的延长,试样的线收缩率和断裂强度呈上升趋势。保温4h,断裂强度达到(497.27±78.45)MPa。观察微观结构可见玻璃相物质均匀分布在陶瓷基体中,晶粒借助于玻璃相物质紧密结合;随着保温时间的延长,材料的微观结构更加均匀。结论采用等静压技术能够提高成型效率,改善陶瓷的烧结性能。

Objective To find out how to prepare high-density dental ceramics through isostatic pressing so that sintering shrinkage will be reduced. Methods To prepare Al2O3/ZrO2 composite powder first, then to mold through dry-pressing, and to shape the green-body through isostatic pressing. The green-bodies were sintered at the tem- perature of 1 400 ℃and kept at the temperature for different period of time （2 h, 3 h, 4 h）. After that, the density and fracture strength were measured and the microstructure observed by scanning electron microscope （SEM）. Results The sample product＇s density, line-shrinkage, and fracture strength of ceramics was rising with the sintering time lengthened. The sample product kept under the temperature of 1 400℃ for 4 hours, the fracture strength was （497.27±78.45） MPa and glass phase distributed evenly in the ceramics and the grains were integrated owing to the glass phase. The longer the sintering time, the more even the microstructure was. Conclusion The sintering quality and the efficiency were improved through isostatic pressing.