氧化锆对二硅酸锂玻璃陶瓷力学性能的影响

目的:测定牙科氧化锆-二硅酸锂玻璃陶瓷复合材料(ZTCLDC)的力学性能,探讨氧化锆质量分数变化对ZTCLDC力学性能的影响及机制。方法:向制备好的二硅酸锂基础玻璃粉体中分别添加不同质量分数的ZrO(21%,2%,3%,4%),静压成型晶化热处理,每组中的半数试件进行牙科热压铸处理,分别测试热压铸前后的三点弯曲强度及断裂韧性;扫描电镜观察晶体微观结构;X射线衍射分析其晶相组成。结果:热压铸前,ZTCLDC抗弯强度和断裂韧性随ZrO2含量的增加而升高;热压铸后,ZTCLDC抗弯强度随ZrO2含量的增加而降低,ZrO2加入量为4%时,压铸后的断裂韧性最高为4.3 MPa.m1/2。结论:ZrO2对实验二硅酸锂玻璃陶瓷存在增韧效果,能够提高复合材料的断裂韧性。

Effect of zirconia content on flexural strength and fracture toughness of dental experimental lithium disilicate glass-ceramic

Objective： The aims of the present study were to evaluate mechanical properties of zirconia - lithium disilicate glass-ceramic composite （ZTCLDC） used for dental application and the effect of different zirconia con-tents on me- chanical properties of ZTCLDC. Method： Four groups of ZTCLDC powders with different zirconia contents were prepared and heat treated. Half specimens in each group were subjected to to dental heat pressing treatment.. The flexural strength and fracture toughness of specimens were evaluated and the microstructure was characterized by scanning electronic micro- scope （SEM）. Crystalline composition of ZTCLDC was also determined using X-ray diffraction （XRD）. Result： Flexural strength of ZTCLDC ceramics before heat treatment, increased as ZrO2 content increased. While for ZTCLDC specimens after heat treatment, flexural strength decreased when ZrO2 content increased. ZTCLDC specimens containing 4 % ZrO2 after heat treatment showed the highest fracture toughness （ 4.3 MPa·m^1/2.） Conclusion： The fracture toughness of the experimental material could be im-proved as the result of addition of ZrO2.