【作者】 杜娟；

【导师】 金学军；

【作者基本信息】 上海交通大学 ， 材料学， 2007， 硕士

【摘要】 本文系统总结了现有的t-ZrO₂纳米晶在低温下稳定存在的各种机制,并对其相关问题进行了试验与分析。（1）在不添加任何分散剂以及表面剂的条件下,运用沉淀法制备出纳米级ZrO₂粉体。（2）随着球磨时间的增长,t相氧化锆的含量降低,m相氧化锆的含量增加,发生了t相向m相的转变。由于晶粒的大小没有发生改变,晶粒内的氧含量也没有发生改变,球磨引入了大量的缺陷,有利于马氏体相变的形核,从而促进了t相到m相的转变。（3）经过淬火处理后的Ce, Y-TZP不但出现驰豫内耗峰,还出现了相变内耗峰。Ce, Y-TZP陶瓷的机械驰豫和介电驰豫均来自于Y_zrV_O偶极子的再取向。（4）纳米氧化锆颗粒的镍基复合镀层,通过不同的制备方案和不断的工艺改造,试图探索最佳的制备方法。更多还原

【Abstract】 Preparation of nanocrystalline ZrO2, co-electrodeposition of nano ZrO2 whiskers nickel composite coating, ball milling of ZrO2 and internal friction of Ce, Y-TZP are investigated. Some new results are presented.(1) The fabricating conditions and processing of nanometer zirconia ceramics powders are introduced. Microstructure of nano zirconia powders is characterized by using Transmission Electron Microscope (TEM) and X-Ray Diffraction (XRD).(2) t-ZrO2 m-ZrO2 occurred by ball milling. The reason is that crystal defects were introduced by ball milling, which goes against of the stabilization of t-ZrO2.(3) The room temperature (RT)-250℃internal friction (IF) for quenched 8Ce, 0.5Y-TZP ceramics and RT-400℃dielectric loss (DL) for 8Ce, 0.5Y-TZP and 8Ce, 0.75Y-TZP ceramics were studied. Along with a relaxation peak, which is typical of normal 8Ce, 0.5Y-TZP, two prominent IF peaks associated with phase transformation were observed in IF spectra for quenched 8Ce, 0.5Y-TZP. The activation energy is discovered to be identical for both the mechanical and dielectric relaxation. More evidences are found that reorientation of更多还原