Tsukrenko V. Physicochemical properties of hydrothermal nanocrystalline powders in the ZrO2-Y2O3-CeO2 -Al2O3-CoO system

It were investigated for the first time the variation of physicochemical properties (phase and chemical composition, morphology, specific surface area, primary particles size) of nanocrystalline powders in the ZrO2-Y2O3-CeO2-Al2O3-СоО system versus heat treatment in the temperature range 400 1300 С for designing colored ZrO2-based composites, which can be resistant to aging in a humid environment. Starting powders were synthesized by hydrothermal synthesis in an alkaline medium and combined method of hydrothermal synthesis/mechanical mixing. It was determined that CoO reduced the temperature of low-temperature phase transformation F-ZrО2-T-ZrО2 and neutralized the Al2O3 influence on this transformation. Sintering temperature of ZrO2-based powders reduced to 1200 С, powders morphology varied topological continuously. It was shown that in the presence of СоAl2O4 the ceramics phase composition after the aging simulation under hydrothermal conditions did not vary. This indicates that blue ZrO2-based composites, produced from nanocrystalline powders in the ZrO2-Y2O3-CeO2 Al2O3-CoO system are characterized by increased resistance to aging.