Thermal behavior and phase transformation of ZrO2–10%SiO2 precursor powder prepared by a co-precipitation route without adding stability agent

Abstract

Thermal behavior and phase transformation of ZrO2–10%SiO2 precursor powder prepared by a co-precipitation route without adding stability agent has been studied using different thermal analysis/thermogravimetry (DTA/TG), X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), nano beam electron diffraction (NBED), high-resolution TEM (HRTEM) and energy-dispersive X-ray spectrometer (EDS). The TG results show that four weight loss regions were from 298 to 443K, 443 to 743K, 743 to 793K and 793 to 1400K. The DTA result shows that the ZrO2 freeze-dried precursor powders crystallization at 1014K. The activation energy of 993.7kJ/mol was obtained for tetragonal ZrO2 crystallization using a non-isothermal process. The XRD result shows that only a single phase of tetragonal ZrO2 appears when the freeze-dried precursor powders after calcination between 1173 and 1373K for 2h. Moreover, when calcined at 1473K for 2h, the phase transformation from tetragonal ZrO2 fully converted to monoclinic ZrO2 occurred.