Shuigen HUANG
,
Lin LI
,
O.V.D.Biest
,
J.Vleugels
,
Peiling WANG
材料科学技术（英）
Using compound energy model (CEM), the thermodynamic properties of and were evaluated. The evaluation was based on the optimization of ZrO2-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 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 . The calculated results seem to be reasonable when put into the explanation of pressureless sintering of CeO2-stabilized ZrO2 powder compacts at a controlled oxygen partial pressure.
关键词:
Zirconia
,
null
,
null
,
null
Lin LI
,
Zhujun TANG
,
Weiying SUN
,
Peiling WANG
材料科学技术（英）
Rare earth oxide systems Al2O3-La2O3 and SiO2-La2O3 were thermodynamically assessed and optimized with the substitution model. The obtained model parameters and Gibbs free energy of line compounds and pure components were applied to the prediction of the liquidus surface and isothermal sections of Al2O3-SiO2-La2O3 system.
关键词:
Shuigen HUANG
,
Lin LI
,
J.Vleugels
,
O.V.D.Biest
,
Peiling WANG
材料科学技术（英）
The ZrO2-CeO2-Al2O3 system has been assessed with the CALPHAD (Calculation of Phase Diagrams) technique using the PARROT procedure. The experimental information on the ZrO2 -Al2O3, Al2O3-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.
关键词:
Ce-TZP
,
null
,
null
Lin LI
,
O.Van Der Biest
,
Peiling WANG
材料科学技术（英）
The application of substitutional model in oxide systems, in comparison with that of sublattice model, is discussed. The results show that in the case of crystalline phases and liquid phases without molecular-like associates or the shortage of element in sublattice, these two models get consistent in the description of the formalism of Gibbs free energies of phases and obtain the same result of phase diagram calculation when the valence of the cations keep the same.
关键词:
Oxide systems
,
null
,
null
