氧化镧协同纳米二氧化硅增韧氧化锆陶瓷及相关机械性能的研究

发布时间：2019-03-12 19:21

【摘要】：目的:将氧化镧(La_2O_3)和纳米二氧化硅(SiO_2)添加到氧化锆陶瓷粉体中,来探索二者的最佳添加比例,以使氧化锆陶瓷的断裂韧性、抗弯强度、维氏硬度及体积密度最佳,并通过扫描电镜观察试件断裂面的显微形态,以探索材料致密度的变化。方法:将La_2O_3和纳米SiO_2按照质量比分别为0、0,0.5wt%、0,1wt%、0,0、0.5wt%,0、1wt%,0.5wt%、0.5wt%,0.5wt%、1wt%,1wt%、0.5wt%,1wt%、1wt%添加到氧化锆陶瓷粉体中,依次为A组、B_1组、B_2组、C_1组、C_2组、D_1组、D_2组、D_3组、D_4组,其中对照组为A组,实验组为B_1、B_2、C_1、C_2、D_1、D_2、D_3和D_4组。将混合后的粉体球磨混匀,脱水干燥,冷等静压成型,采用两段式烧结工艺进行无压固相烧结,得到断裂韧性试件,规格为25 mm×2.5 mm×5 mm,同时得到抗弯强度和硬度试件,规格为35 mm×3 mm×4 mm,在磨抛机上研磨上下表面,在丙酮和无水乙醇中分别超声清洗,烘干、备用,进行断裂韧性、抗弯强度、维氏硬度及体积密度测试,用扫描电镜随机观察断裂韧性试件断裂面的显微形态进而确定其致密度。结果:除D_3和D_4组外,其余组的断裂韧性、抗弯强度、维氏硬度及体积密度均有显著差异(P0.05);比较B组和C组,发现在改善氧化锆陶瓷性能方面,La_2O_3优于纳米SiO_2;且C_2组优于C_1组,B_1组优于B_2组;D_2组最佳。扫描电镜观察显示D_2组晶粒均匀紧密排列,完全致密;D_3、D_4组致密度低于A组,其余组优于A组低于D_2组。结论:在改善氧化锆陶瓷性能方面,La_2O_3和纳米SiO_2起协同作用,且La_2O_3优于纳米SiO_2,且当La_2O_3的添加量为0.5wt%,纳米SiO_2的添加量为1wt%时,氧化锆陶瓷的机械性能最佳。
[Abstract]:Objective: to explore the optimum addition ratio of lanthanum oxide (La_2O_3) and nano-silica (SiO_2) to zirconia ceramic powder in order to make the fracture toughness and bending strength of zirconia ceramics. Vickers hardness and volume density were the best. The micromorphology of fracture surface was observed by scanning electron microscope in order to explore the change of the density of the material. Methods: the mass ratios of La_2O_3 and nano-SiO_2 were 0,0,0.5wt%, 0,1wt%, 0,0,0.5wt%, 0,1wt%, 0.5wt%, 0.5wt%, 0.5wt%, 0.5wt%, 1WT%, 0.5wt%, 1wt%, 1WT%, 0.5wt%, 1WT%, respectively, and the mass ratio was 0,0,0.5wt%, 0.5wt%, 0wt%, 0.5wt%, 0.5wt%, 1WT%, 0.5wt%, 0.5wt%, 1wt%, respectively. 1 wt% was added to zirconia ceramic powder, followed by group A, group B, group C, group D, group 2, group D, group A, group B, group B, C, D, D and D groups. The mixed powder was ball-milled, dehydrated and dried, and formed by cold isostatic pressing. The fracture toughness specimens were obtained by two-stage sintering process without pressing and solid phase sintering. The bending strength and hardness samples were obtained at the same time with the specification of 25 mm 脳 2.5 mm 脳 5 mm,. The specification is 35 mm 脳 3 mm 脳 4 mm, for grinding the upper and lower surfaces on the polishing machine, ultrasonic cleaning, drying, and standby in acetone and absolute ethanol, respectively. Fracture toughness, bending strength, Vickers hardness and volume density are tested. The micromorphology of fracture toughness specimen was observed by scanning electron microscope (SEM) and the density of fracture toughness specimen was determined. Results: there were significant differences in fracture toughness, bending strength, Vickers hardness and volume density between the other groups except D + 3 and D + 4 (P0.05). Compared with group B and C, it was found that La_2O_3 was superior to nano-SiO_2; in improving the properties of Zirconia ceramics, C _ (2) was superior to C _ (?) 1, B _ (?) 1 was better than B _ (?) 2, and D _ (?) 2 was the best. Scanning electron microscopy (SEM) showed that the grain density of group D _ (3), D _ (4) was lower than that of group A, and that of other groups was better than that of group A, and that of group D ~ (2) was better than that of group A (P < 0.05). Conclusion: in improving the properties of zirconia ceramics, La_2O_3 and nano-SiO_2 have synergistic effect, and La_2O_3 is superior to nano-SiO_2, and when the addition of La_2O_3 is 0.5 wt%, The mechanical properties of zirconia ceramics were the best when the addition of nano-SiO_2 was 1 wt%.
【学位授予单位】：佳木斯大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R783.1

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