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目的 :研究烧结温度对凝胶注模成型牙科氧化锆增韧氧化铝(zirconia toughened alumina,ZTA)陶瓷力学性能的影响。方法:经凝胶注模成型工艺制备的ZTA陶瓷坯体,分别烧结至1100、1200、1250、1300、1400℃,测定不同烧结温度组试件的三点抗弯强度、断裂韧性、维氏硬度,计算脆性指数;用扫描电镜观察三点弯曲试验后试件断面的显微形貌。采用SPSS 19.0软件包对数据进行统计学分析。结果:在1100~1400℃范围内,ZTA的三点抗弯强度、断裂韧性和维氏硬度均随着烧结温度的升高而增大;脆性指数的最小、最大值分别见于1200℃和1400℃温度组(P<0.05),为(0.74±0.16)μm~(-1/2)和(2.76±0.14)μm~(-1/2),两者的抗弯强度分别为(46.89±3.24)MPa和(349.64±54.72)MPa。结论 :凝胶注模成型的ZTA陶瓷在合适的烧结温度(1200℃)下具有较佳的可加工性能及一定的机械强度,初步满足临床牙科陶瓷加工的需求。
Objective: To study the effect of sintering temperature on the mechanical properties of zirconia toughened alumina (ZTA) ceramics by gelcasting. Methods: ZTA ceramic bodies prepared by gelcasting were sintered to 1100, 1200, 1250, 1300 and 1400 ℃, respectively. The three-point bending strength, fracture toughness, Vickers hardness The brittleness index was calculated. The microstructure of the specimen after three-point bending test was observed by scanning electron microscope. Data were statistically analyzed using SPSS 19.0 software package. Results: Three-point bending strength, fracture toughness and Vickers hardness of ZTA increased with sintering temperature in the range of 1100 ~ 1400 ℃. The minimum and maximum brittleness index were found at 1200 ℃ and 1400 ℃ respectively (0.74 ± 0.16) μm -1 (-1/2) and (2.76 ± 0.14) μm -1 (-1/2), respectively. The flexural strengths of the two groups were (46.89 ± 3.24) MPa and (349.64 ± 54.72) MPa. Conclusion: The gel-cast ZTA ceramics have better machinability and mechanical strength at the proper sintering temperature (1200 ℃), and meet the needs of clinical dental ceramics.