首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
The optimized thermodynamic data for the Te- TI binary system have been obtained by the computer operated least squares method from measured data. The Gibbs energy of the liquid phase was modeled as a two- sublattice model for ionic melt after Hillert.31 The intermediate compounds, Te3Tl{2}and TeTl, were treated as stoichiometric phases, and the nonstoichiometric γ phase was expressed as a sublattice model. A strong tendency for chemical short- range order in the liquid state at the composition close to TeTh was confirmed by calculated results, but the existence of the TeTh phase was not justified. The experimental thermodynamic and phase diagram data were closely reproduced by the optimized thermodynamic data. Parameters describing the Gibbs energies of all the phases in this calculation and the calculated phase diagram and thermodynamic functions are presented and compared with experimental information.  相似文献   

2.
The optimized thermodynamic data for the Te- TI binary system have been obtained by the computer operated least squares method from measured data. The Gibbs energy of the liquid phase was modeled as a two- sublattice model for ionic melt after Hillert.31 The intermediate compounds, Te3Tl{2}and TeTl, were treated as stoichiometric phases, and the nonstoichiometric γ phase was expressed as a sublattice model. A strong tendency for chemical short- range order in the liquid state at the composition close to TeTh was confirmed by calculated results, but the existence of the TeTh phase was not justified. The experimental thermodynamic and phase diagram data were closely reproduced by the optimized thermodynamic data. Parameters describing the Gibbs energies of all the phases in this calculation and the calculated phase diagram and thermodynamic functions are presented and compared with experimental information.  相似文献   

3.
The calculation of phase diagram (CALPHAD) technique has been used to carry out the thermodynamic assessment of the Al-Pt binary system. Seven intermetallics are considered as stable phases in addition to the terminal solid solutions. The set of Gibbs energy functions with optimized parameters is used to calculate the Al-Pt binary phase diagram as well as the thermodynamic properties in good agreement with the experimental results.  相似文献   

4.
The calculation of phase diagram (CALPHAD) technique has been used to carry out the thermodynamic assessment of the Al-Pt binary system. Seven intermetallics are considered as stable phases in addition to the terminal solid solutions. The set of Gibbs energy functions with optimized parameters is used to calculate the Al-Pt binary phase diagram as well as the thermodynamic properties in good agreement with the experimental results.  相似文献   

5.
All available thermodynamic and phase diagram data were critically assessed for all phases in the Al-Mg, Al-Sr, and Mg-Sr systems at 1 bar pressure from room temperature to above the liquidus temperatures. For these systems, all reliable data were simultaneously optimized to obtain a set of model equations for the Gibbs energy of the liquid alloy and all solid phases as functions of composition and temperature. The modified quasi-chemical model was used for the liquid. The Al-Mg-Sr ternary phase diagram was calculated from the optimized thermodynamic properties of the binary systems. Since no reliable ternary data were available, three assumptions were made: no ternary terms were added to the model parameters for the thermodynamic properties of the liquid, no ternary solid solutions are present in the system, and no ternary compound is present in the system. The calculated ternary phase diagram is thus a first approximation, which can be improved by the addition of new experimental data and can be used as a base for the calculation of phase diagrams of multicomponent systems.  相似文献   

6.
The Ni-Sb binary alloy system was thermodynamically assessed using CALPHAD approach in this article.Excess Gibbs energies of solution phases,liquid and fcc phases,were formulated using the Redlich-Kister expression.The intermediate phases were modeled by the sublattice model with (Ni,Va)0.5(Ni,Sb)0.25(Ni)0.25 for Ni3Sb_HT phase and (Ni,Va)0.3333(Sb)0.3333(Ni,Va)0.3333 for NiSb phase.The other phases including Ni3Sb,Ni7Sb3,and NiSb2 were treated as stoichiometric compound owing to their narrow composition ranges.Based on the reported thermodynamic properties and phase diagram data,the thermodynamic parameters of these phases were optimized,and the obtained values can reproduce the available experimental data well.  相似文献   

7.
According to measured experimental phase diagram data and thermodynamic data, the HoCl3-MCl (M = Na, K, Rb, Cs) phase diagrams were determined by the CALPHAD technique. The Gibbs energies of liquid phases in these systems have been optimized and calculated by the modified quasi-chemical model in the pair-approximation for short-range ordering. A series of thermodynamic functions have been optimized and calculated on the basis of an interactive computer-assisted analysis. The results show that the thermodynamic properties and phase diagrams are self-consistent. The optimized results for the systems are discussed.  相似文献   

8.
9.
A thermodynamic assessment of the Al-Cu-Mg ternary system   总被引:3,自引:0,他引:3  
A thermodynamic assessment of the Al-Cu-Mg ternary system is presented. The Gibbs energies for the liquid and solid solution phases were modeled using the Redlich-Kister polynomial and the Wagner-Schottky model represented by the compound-energy formalism. The model parameters were obtained after fitting to previously critically assessed experimental phase diagram and thermodynamic data available in the literature. The thermodynamic functions and phase diagram calculated using the model parameters describe quite well the known experimental information. The complete set of Gibbs energies for all phases appearing in this system enables the calculation of thermodynamic values as a function of composition and temperature even for those ranges where no experimental information is available.  相似文献   

10.
1 IntroductionRE AlandRE Al Mearepotentialamorphousalloy[1]andhydrogen absorbingmaterials[2 ].RareEarth ,asadditionalele mentsinaluminumandAl transitionmetalsalloy ,canimprovemechanicalpropertiesofthefinalmaterials[3].Thephasediagramandthermodynamicpropertiesoft…  相似文献   

11.
12.
The O-Ti binary system has been assessed to produce Gibbs energy parameters for the condensed phases and were evaluated as representations of thermodynamic models. The liquid phase was described in terms of an association model with one associate, the bcc, A 2; cph, A 3 and fcc, A 1 phases were described as interstitial solid solutions, and the O2Ti, O3Ti5, O3Ti2, and OTi oxides were considered to be stoichiometric compounds. The thermodynamic parameters were optimized taking into account experimental phase diagram and thermodynamic values from the literature. The phase diagram and the thermodynamic properties were calculated and compared with experimental data.  相似文献   

13.
The C-Mo-Zr system was assessed by means of the CALPHAD approach. All of the phase equilibria available from the literature were critically reviewed. The liquid was modeled as substitutional solution phase, while the carbides including fcc-(Mo,Zr)C1?x, bcc-(Mo), bcc-(Zr), hcp-Mo2C, hcp-(Zr) and η-MoC were described by using corresponding sublattice models. The laves-Mo2Zr and shp-MoC phases were considered as binary compounds with no solubility for the third component. The existence of ternary phase was not reported in this system. The modeling of C-Mo-Zr ternary system covers the entire composition and temperature ranges, and a set of self-consistent thermodynamic parameters for the C-Mo-Zr system was systematically optimized. Comprehensive comparisons between the calculated and reported phase diagram data show that the reliable information is satisfactorily accounted for by the present modeling. The liquidus projection and reaction scheme of the C-Mo-Zr system were also generated based on the present thermodynamic assessment.  相似文献   

14.
15.
Phase equilibria and thermodynamic data of the Al-Re system are critically reviewed. In addition to the three solution phases, liquid, fcc Al, and hcp Re, there exist six intermetallic compounds in this binary. The thermodynamic properties of the system are analyzed using thermodynamic models for the Gibbs energy of individual phases of the system. A regular solution model is used for the three substitutional solution phases, and the intermetallic phases are treated as stoichiometric compounds. The model parameters are optimized from a limited amount of experimental data. The calculated phase diagram and thermodynamic values are in accord with the available experimental values.  相似文献   

16.
Based on an assessment of the available experimental thermochemical and phase diagram information available, the phase equilibria of the C-Hf-Zr system were calculated. The G of the individual phases was described with thermodynamic models. The liquid phase was described as a substitutional solution using the Redlich-Kister formalism for excess G. Graphite was treated as a stoichiometric phase. The solid solutions of carbon in α(Hf,Zr) and β(Hf,Zr), as well as the non-stoichiometric phase (Hf,Zr)C1?x, were represented as interstitial solid solutions using the compound energy model with two sublattices. The parameters in the models were determined by computerized optimization using selected experimental data. A detailed comparison was made between calculation and experimental data.  相似文献   

17.
An optimized set of thermodynamic functions for the K2O-SiO2 system at 105 Pa pressure was obtained by considering available phase diagram and thermodynamic data. KSi0.25O and SiO2 were selected as components for the liquid phase. With respect to these components, the highly non-ideal interactions of potassium oxide and silica could be described by using only three temperature-independent Redlich-Kister coefficients for the excess G of the liquid phase. The result is in good agreement with experimental data.  相似文献   

18.
《Intermetallics》2007,15(1):77-84
Phase equilibria in the Ag–In–Pd system were determined at 500 °C based on experimental results for 16 alloys. A ternary intermetallic compound (T1) in the palladium-rich region was confirmed by X-ray diffractometry. The experimental data were first compared with the results of a CALPHAD-type prediction, based on binary thermodynamic data using only a symmetrical Redlich–Kister–Muggianu model. In a second step, the thermodynamic modeling of the different phases in this ternary system was refined by including ternary interactions, and the phase diagram was calculated for the temperature range between 500 and 700 °C. With the optimized thermodynamic parameters the phase diagram was extrapolated to 200 °C and compared with preliminary experimental results.  相似文献   

19.
A thermodynamic modeling of the CeO2–CoO phase diagram was performed with recent experimental data. The excess Gibbs energies of the solution phases were described on the basis of the simple regular solution. A consistent set of optimized interaction parameters was derived for describing the Gibbs energy of each phase in this system leading to a good fit between calculation and experimental data. The liquidus, solidus, and solvus curves were calculated and also the lattice stabilities of the components were evaluated.  相似文献   

20.
PhaseEquilibriaCalculationoftheGaInSbTernarySystemXieYun′an,QiaoZhiyu,XingXianranandWangCong(谢允安)(乔芝郁)(邢献然)(王聪)Dept.ofPhys...  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号