二次烧结温度对牙科氧化锆陶瓷组织和力学性能的影响

Effect of the Second Sintering Temperature on Microstructure and Mechanical Properties of Dental ZirconiaCeramic

研究二次烧结温度对氧化锆牙科陶瓷微观组织和力学性能的影响。方法为氧化锆亚微米粉经过干压、冷等静压成型后在1050℃预烧结，然后将预烧结牙科氧化锆瓷块在1300～1600℃进行二次烧结。对不同二次烧结温度下材料的线收缩率、烧结密度、物相、三点抗弯强度进行测量分析，并通过扫描电镜观察试样的断面形貌。结果表明随着二次烧结温度提高，氧化锆的密度、弯曲强度呈上升趋势。在1350℃时体积密度达到6．10g／cm3，1500℃时的机械性能最优，三点弯曲强度为852MPa，主晶相为四方相。结论是亚微米氧化锆粉体烧结活性高，力学性能优良，能够满足口腔全瓷修复材料的要求。

To study the effects of the second sintering temperature on the microstructure and me- chanical properties of zirconia dental ceramic. Methods： Submicron zireonia powder was dry compac- ted, cold isostatic pressed and pre-sintered at 1050℃. Then the pre-sintered zirconia blocks were sintered for the second time at temperature between 1300 and 1600℃. The density, main phase, three -point bending strength and fracture surface microstructure of the twice sintered samples were inves- tigated. Results： The results showed that the sintered density, three-point bending strength in- creased with sintering temperature increased. The sintered density reached to 6.10 g/ cma at 1350℃. The best mechanical properties of the materials were obtained at sintering temperature of 1500℃ at which bending strength of 852 MPa. The main phase was confirmed as tetragonal. Conclusions： The dental submicron zirconia powders have highly sintering activity, excellent mechanical properties to fit the requirement of dental use.