共沸蒸馏法制备牙科氧化锆纳米晶微粉的研究

Preparation of nanometer crystalline powder of dental ZrO_2 ceramics by heterog eneous azeotropic distillation

目的 :探讨用于制备高性能氧化锆牙科陶瓷的氧化锆纳米晶微粉的方法与条件。方法 :采用非均相共沸蒸馏法以正丁醇为夹带剂对水合氢氧化锆凝胶进行脱水 ,比较在减压、常压条件下和直接用乙醇洗脱水所制备的氧化锆粉体的性能。结果 :水合氢氧化锆凝胶经干燥煅烧后 ,成功制成了氧化锆纳米晶微粉。直接用乙醇洗脱水 ,粉体的dBET约为 2 5nm ;在减压共沸蒸馏的条件下 ,粉体的dBET约为 2 2nm ;在常压共沸蒸馏的条件下 ,粉体的dBET约为 17nm。 3种粉体模压成型 ,无压烧结得到陶瓷的弯曲强度分别为 660、710、64 0MPa ,断裂韧性分别为 4.3 4、4.77、4.2 4MPa·m1/ 2 。结论 :用常压共沸蒸馏法能有效地克服硬团聚的形成 ,制得粒径较小。

Objective: To explore the preparation methods of nanomete r powder of ZrO 2 for dental application. Methods:Zirconia gel wa s dehydrated by heterogeneous azeotropic distillation process and n-butanol was used as azeotropic solvent. The properties of ultrafine powder obtained via dec ompression (process b), atmosphere pressure (process c) and direct ethanol-wash ing (process a) were studied. Results: After drying and calcini ng the gel, the ultrafine powder obtained from process a,b and c was about 25 n m,22 nm and 17 nm respectively. 3Y-TZP ceramic prepared with the three kinds of nanometer powder had bending strength of 660 MPa,710 MPa and 640 MPa; fracture toughness of 4.34 MPa·m 1/2 ,4.77 MPa·m 1/2 and 4.24 MPa·m 1/2 , respectively. Conclusion: By the heterogeneous azeotropic dis tillation process, zirconia ultrafine powder without hard agglomeration (d BE T=17 nm) can be obtained.