Using compound energy model (CEM), the thermodynamic properties of <CeO2-y> and <Zr1_xCezO2-x> were evaluated. The evaluation was based on the optimization of ZrIO2-CeO2 and ZrO2-CeO1.5 systems, as well as...Using compound energy model (CEM), the thermodynamic properties of <CeO2-y> and <Zr1_xCezO2-x> were evaluated. The evaluation was based on the optimization of ZrIO2-CeO2 and ZrO2-CeO1.5 systems, as well as the miscibility gap in CeO1.5-CeO2 system. Except the cubic fluorite structure phase assessed with compound energy model, all the other solution phases were assessed with subsitutional solution model. The model parameters were evaluated through fitting the selected experimental data by means of thermodynamic optimization. A set of parameters with thermodynamics self-consistency was obtained and satisfactorily described the complex relation between y in <CeO2-y> and the partial pressure of oxygen at different temperatures, also the interdependence among miscellaneous factors such as temperature, oxygen partial pressure, the reduction amount of CeO2 as well as the nonstoichiometry in cubic phase <Zr1-xCezO2-x>- The calculated results seem to be reasonable when put into the explanation of pressureless sintering of Ce02-stabilized ZrO2 powder compacts at a controlled oxygen partial pressure.展开更多
The ZrO2-CeO2-AI2O3 system has been assessed with the CALPHAD (Calculation of Phase Diagrams) technique using the PARROT procedure. The experimental information on the ZrO2-AI2O3, AI2O3-CeO2 systems as well as the iso...The ZrO2-CeO2-AI2O3 system has been assessed with the CALPHAD (Calculation of Phase Diagrams) technique using the PARROT procedure. The experimental information on the ZrO2-AI2O3, AI2O3-CeO2 systems as well as the isothermal sections of the ternary system at 1673 K and 1873 K is well reproduced. According to the assessed isothermal section at 1723 K, no alumina dissolves into the tetragonal zirconia phase. Specimens with different alumina content are fabricated from commercial 12 mol pct CeO2-stabilized ZrO2 powder (12Ce-ZrO2). The thermodynamic properties are consistent with the observed microstructure, which present a combination of tetragonal phase and alumina grains.展开更多
基金This paper is financially supported by the Flanders-China bilateral project (BIL 99/10)the Science and Technology Committee of Shanghai Municipality +1 种基金the State Key Lab of High Performance Ceramics Superfine Microstructure of Chinese Academy of Scien
文摘Using compound energy model (CEM), the thermodynamic properties of <CeO2-y> and <Zr1_xCezO2-x> were evaluated. The evaluation was based on the optimization of ZrIO2-CeO2 and ZrO2-CeO1.5 systems, as well as the miscibility gap in CeO1.5-CeO2 system. Except the cubic fluorite structure phase assessed with compound energy model, all the other solution phases were assessed with subsitutional solution model. The model parameters were evaluated through fitting the selected experimental data by means of thermodynamic optimization. A set of parameters with thermodynamics self-consistency was obtained and satisfactorily described the complex relation between y in <CeO2-y> and the partial pressure of oxygen at different temperatures, also the interdependence among miscellaneous factors such as temperature, oxygen partial pressure, the reduction amount of CeO2 as well as the nonstoichiometry in cubic phase <Zr1-xCezO2-x>- The calculated results seem to be reasonable when put into the explanation of pressureless sintering of Ce02-stabilized ZrO2 powder compacts at a controlled oxygen partial pressure.
基金supported by the Flanders-China bilateral project(BIL 99/10)the Science and Technology Committee of Shanghai Municipalitythe Commission of the European Communities in the framework of the Growth Project"BIOGRAD"(G5RD-CT2000-00354)
文摘The ZrO2-CeO2-AI2O3 system has been assessed with the CALPHAD (Calculation of Phase Diagrams) technique using the PARROT procedure. The experimental information on the ZrO2-AI2O3, AI2O3-CeO2 systems as well as the isothermal sections of the ternary system at 1673 K and 1873 K is well reproduced. According to the assessed isothermal section at 1723 K, no alumina dissolves into the tetragonal zirconia phase. Specimens with different alumina content are fabricated from commercial 12 mol pct CeO2-stabilized ZrO2 powder (12Ce-ZrO2). The thermodynamic properties are consistent with the observed microstructure, which present a combination of tetragonal phase and alumina grains.
