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[O63] Application of Computational Thermodynamics in Solid Oxide Fuel Cell
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Y. DU et al. / CALPHAD: Computer Coupling of Phase Diagrams and Thermochemistry 51 (2015) 344–415
[O61] Critical evaluation and thermodynamic optimization of the V-O system Shuai Li, Wei Xie, Zhiyu Qiao, Zhanmin Cao
Critical evaluation and thermodynamic optimization of phase diagrams and thermodynamic properties of the V-O system are presented. The liquid phase over the entire composition range from metallic liquid to oxide melt is described by the modified quasichemical model, which takes short-range ordering into account. (V)ss, (VO)ss, and (V2O3)ss solid solutions are modeled using the simple random mixing models, while (V4O)ss and (V2O)ss solid solutions are described by the two-sublattice models. All other solid phases are treated as stoichiometric compounds. A set of self-consistent thermodynamic parameters of the V-O system is obtained using the CALPHAD technique, and the available phase equilibrium and thermodynamic data are reproduced well within experimental error limits. The present study can be used as a basis for development of a thermodynamic database for the vanadium containing alloys and slag systems. Also, it is a part of an ongoing research project which is aimed at developing a thermodynamic database of the Fe-V-Ti-O system with the purpose of smelting vanadium-titanium magnetite. Fig. 4 shows the present calculated V-O phase diagram at 1 atm. http://dx.doi.org/10.1016/j.calphad.2015.01.066
[O62] Experimental investigate and thermodynamic assessment of the Ca-Y, Mg-Ca-Y, Ce-Sr and Mg-Ce-Sr system Cuiyun He, Songxiang Sun, Hua Zhou, Peisheng Wang, Yong Du
Based on XRD, SEM/EDS and DSC method, the phase equilibria of Ca-Y and Ce-Sr binary systems had been investigated, isothermal section at 400 oC of Mg-Ca-Y and Mg-Ce-Sr system had been determined and some as-cast alloys at Mg-rich part of both ternary systems had been studied. No binary compound was found in Ca-Y and Ce-Sr binary systems, and no ternary compound was found in Mg-Ca-Y and Mg-Ce-Sr system also. In the Mg-Ca-Y
system, Mg2Ca, Mg2Y are detected to dissolve about 6 to 15 at.% third element, MgY and Mg24Y5 contain about 3 to 8 at.% Ca at 400 o C. In the Mg-Ce-Sr system, six binary phases Mg2Sr, Mg23Sr6, Mg38Sr9, Mg17Sr2, Mg12Ce, Mg41Ce5 are detected, dissolving about 3 to 7 at.% third element at 400 oC. Based on literature data and our own experimental data, the binary systems Ca-Y and Ce-Sr and two ternary systems Mg-Ca-Y and Mg-Ce-Sr had been optimized respectively. The agreement between calculation and experimental data is reasonable for the above investigated systems. http://dx.doi.org/10.1016/j.calphad.2015.01.067
[O63] Application of Computational Thermodynamics in Solid Oxide Fuel Cell Yu Zhong, Mei Yang, Ming Chen
High sintering and operation temperatures promote unwanted interface reactions in Solid Oxide Fuel Cell (SOFC), especially at the cathode-air-electrolyte triple phase boundary (TPB). The phase stability at TPB has been identified as the dominant mechanism for the long-term degradation, which is a critical parameter for SOFC. It is greatly needed to use the CALPHAD approach to investigate the phase equilibria between the cathode (perovskite) and the electrolyte (doped zirconia). The presentation will cover the following two topics: The thermodynamic database development of cathode (perovskite). LaCoO3-δ is chosen for the current presentation. The choice of the thermodynamic model and the defect chemistry involved will be discussed. Significant Co3 þ charge disproportionation is predicted. The combined approach with Computational Thermodynamics and experiments has been used to investigate the phase stabilities at TPB. Srsubstituted LaMnO3 perovskite (LSM) and yttriastabilized zirconia (YSZ) mixture was investigated by thermodynamic calculations to understand the factors affecting the stabilities of La2Zr2O7 (LZO) and SrZrO3 (SZO), the two zirconates, at different conditions. Experimental investigations were done on the thermodynamic stabilities of the two zirconates in N2 and air to simulate the phase equilibria at different conditions. The experimental data proved that thermodynamic calculations were reliable and they can be used to provide guidance on the control of the phase stability at TPB. http://dx.doi.org/10.1016/j.calphad.2015.01.068
[O64] Application of CALPHAD method on the cracking control of Nb-containing bulk zirconium hydride Jianwei Wang, Lijun Wang, Ligen Wang, Guojie Huang, Lei Cheng, Wei Xiao
Fig. 4. The present calculated V-O phase diagram at 1 atm.
Zirconium hydride in the solid state with high thermal stability and hydrogen content, low thermal neutron absorption cross section, good mechanical properties and negative reaction factor
Y. DU et al. / CALPHAD: Computer Coupling of Phase Diagrams and Thermochemistry 51 (2015) 344–415
[O61] Critical evaluation and thermodynamic optimization of the V-O system Shuai Li, Wei Xie, Zhiyu Qiao, Zhanmin Cao
Critical evaluation and thermodynamic optimization of phase diagrams and thermodynamic properties of the V-O system are presented. The liquid phase over the entire composition range from metallic liquid to oxide melt is described by the modified quasichemical model, which takes short-range ordering into account. (V)ss, (VO)ss, and (V2O3)ss solid solutions are modeled using the simple random mixing models, while (V4O)ss and (V2O)ss solid solutions are described by the two-sublattice models. All other solid phases are treated as stoichiometric compounds. A set of self-consistent thermodynamic parameters of the V-O system is obtained using the CALPHAD technique, and the available phase equilibrium and thermodynamic data are reproduced well within experimental error limits. The present study can be used as a basis for development of a thermodynamic database for the vanadium containing alloys and slag systems. Also, it is a part of an ongoing research project which is aimed at developing a thermodynamic database of the Fe-V-Ti-O system with the purpose of smelting vanadium-titanium magnetite. Fig. 4 shows the present calculated V-O phase diagram at 1 atm. http://dx.doi.org/10.1016/j.calphad.2015.01.066
[O62] Experimental investigate and thermodynamic assessment of the Ca-Y, Mg-Ca-Y, Ce-Sr and Mg-Ce-Sr system Cuiyun He, Songxiang Sun, Hua Zhou, Peisheng Wang, Yong Du
Based on XRD, SEM/EDS and DSC method, the phase equilibria of Ca-Y and Ce-Sr binary systems had been investigated, isothermal section at 400 oC of Mg-Ca-Y and Mg-Ce-Sr system had been determined and some as-cast alloys at Mg-rich part of both ternary systems had been studied. No binary compound was found in Ca-Y and Ce-Sr binary systems, and no ternary compound was found in Mg-Ca-Y and Mg-Ce-Sr system also. In the Mg-Ca-Y
system, Mg2Ca, Mg2Y are detected to dissolve about 6 to 15 at.% third element, MgY and Mg24Y5 contain about 3 to 8 at.% Ca at 400 o C. In the Mg-Ce-Sr system, six binary phases Mg2Sr, Mg23Sr6, Mg38Sr9, Mg17Sr2, Mg12Ce, Mg41Ce5 are detected, dissolving about 3 to 7 at.% third element at 400 oC. Based on literature data and our own experimental data, the binary systems Ca-Y and Ce-Sr and two ternary systems Mg-Ca-Y and Mg-Ce-Sr had been optimized respectively. The agreement between calculation and experimental data is reasonable for the above investigated systems. http://dx.doi.org/10.1016/j.calphad.2015.01.067
[O63] Application of Computational Thermodynamics in Solid Oxide Fuel Cell Yu Zhong, Mei Yang, Ming Chen
High sintering and operation temperatures promote unwanted interface reactions in Solid Oxide Fuel Cell (SOFC), especially at the cathode-air-electrolyte triple phase boundary (TPB). The phase stability at TPB has been identified as the dominant mechanism for the long-term degradation, which is a critical parameter for SOFC. It is greatly needed to use the CALPHAD approach to investigate the phase equilibria between the cathode (perovskite) and the electrolyte (doped zirconia). The presentation will cover the following two topics: The thermodynamic database development of cathode (perovskite). LaCoO3-δ is chosen for the current presentation. The choice of the thermodynamic model and the defect chemistry involved will be discussed. Significant Co3 þ charge disproportionation is predicted. The combined approach with Computational Thermodynamics and experiments has been used to investigate the phase stabilities at TPB. Srsubstituted LaMnO3 perovskite (LSM) and yttriastabilized zirconia (YSZ) mixture was investigated by thermodynamic calculations to understand the factors affecting the stabilities of La2Zr2O7 (LZO) and SrZrO3 (SZO), the two zirconates, at different conditions. Experimental investigations were done on the thermodynamic stabilities of the two zirconates in N2 and air to simulate the phase equilibria at different conditions. The experimental data proved that thermodynamic calculations were reliable and they can be used to provide guidance on the control of the phase stability at TPB. http://dx.doi.org/10.1016/j.calphad.2015.01.068
[O64] Application of CALPHAD method on the cracking control of Nb-containing bulk zirconium hydride Jianwei Wang, Lijun Wang, Ligen Wang, Guojie Huang, Lei Cheng, Wei Xiao
Fig. 4. The present calculated V-O phase diagram at 1 atm.
Zirconium hydride in the solid state with high thermal stability and hydrogen content, low thermal neutron absorption cross section, good mechanical properties and negative reaction factor