Study Of Mechanisms Of Room Temperature Metastable Tetragonal Phase Stabilisation In Zirconia

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...