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1.
Cuiping Wang Yihui Guo Yong Lu Xingjun Liu 《Journal of Phase Equilibria and Diffusion》2014,35(3):269-275
The thermodynamic assessment of the binary system Ti-Ir has been carried out by modeling the Gibbs energy of all individual phases using the calculation of phase diagrams approach based on the available literature data including the phase equilibria and thermodynamic properties. The Gibbs free energies of the liquid, bcc, fcc and hcp phases were described by the subregular solution model with Redlich-Kister formula, and those of the intermetallic compounds (Ti3Ir, γTiIr, βTiIr and TiIr3) in the Ti-Ir binary system were described by the two-sublattice model. The calculations are in good agreement with the literature data on both phase equilibria and thermodynamic properties in the Ti-Ir system. 相似文献
2.
利用相图计算(CALPHAD)方法,采用亚规则溶体模型描述溶体相的吉布斯自由能,采用亚点阵模型描述金属间化合物和有序相的吉布斯自由能,并结合相平衡和热力学性质的实验数据,优化与计算Cu-X二元系以及Cu-Fe、Cu-Ni、Cu-Cr、Cu-Co、Cu-Mo和Cu-W基各三元系的相图,获得自洽性良好的热力学参数,并建立铜合金热力学数据库。该数据库可以提供稳定和亚稳的相图计算、相分数计算、液相面计算、热力学性质的计算等多种信息,为外推计算铜基多元合金系的相平衡提供理论基础,并为高性能铜合金材料的设计及制备提供重要的理论指导。 相似文献
3.
《Acta Materialia》2002,50(9):2223-2232
Two-phase equilibria between the ferromagnetic fcc and the paramagnetic fcc phase from 800 to 900 °C in the Co-rich region was determined using the diffusion couple technique. It was confirmed that a magnetically-induced miscibility gap of the fcc phase is formed along the Curie temperature.Thermodynamic calculation of the phase equilibria of the Co–Cr system was performed by optimizing the present results and the thermodynamic data in the literature. A set of thermodynamic values for describing the Gibbs energy of liquid, fcc hcp, bcc and sigma phases yielded good agreement between the calculated phase diagram and the experimental data. Moreover, the magnetically-induced miscibility gap between the ferromagnetic and paramagnetic hcp phases was also predicted. This kind of thermodynamic calculation of Co–Cr base alloys is quite useful for the alloy design of the magnetic recording media. 相似文献
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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
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Iikka ISOMÄKI Rui ZHANG Long-gong XIA Niko HELLSTEN Pekka A. TASKINEN 《中国有色金属学会会刊》2018,28(9):1869-1877
ZnO-containing slags are common in pyrometallurgical processing of the base metals and steel. This caused the interest to the thermodynamics of the ZnO-SiO2 system. A complete literature survey, critical evaluation of the available experimental data and a thermodynamic optimization of the phase equilibria and thermodynamic properties of the system ZnO-SiO2 at 1.013×105 Pa are presented. The molten oxide was described as an associate solution. The properties of liquid were reassessed and enthalpy term of the Gibbs energy of solid Zn2SiO4 was re-fitted to be compatible with the new data in the willemite primary phase field. The thermodynamic data set agrees well with the recent experimental observations. It can be used for predicting, e.g., the thermodynamic properties and the domains of the phase diagram, like critical point of the liquid miscibility gap, with a better accuracy than using the previous assessments. A set of optimized model parameters were obtained, reproducing the reliable thermodynamic and phase equilibrium data within their experimental errors from 298 K to liquidus temperatures, over the entire composition range. The created database can be used in a Gibbs energy minimization software to calculate the thermodynamic properties and the phase diagram sections of interest. 相似文献
8.
A thorough review and critical evaluation of phase equilibria and thermodynamic data for all phases in the iron-sulfur (Fe-S)
binary system at 1 bar pressure has been made over the entire composition range for temperatures from 25 °C to above the liquidus.
The Gibbs energies of ten phases have been modeled, and optimized model parameters have been obtained that reproduce all data
simultaneously within experimental error limits. For the liquid phase, the recently extended modified quasi-chemical model
is applied for the first time to a liquid metal-sulfur phase. A two-sublattice model within the framework of the compound
energy formalism is used for the high-temperature monosulfide pyrrhotite solution. A substitutional model is used for the
dissolution of S in solid iron. The Gibbs energies of six stoichiometric compounds are also modeled. 相似文献
9.
Dong Wang Jianhua Zhu Shangheng Wang Hongtao Chen Xingjun Liu Cuiping Wang 《Journal of Phase Equilibria and Diffusion》2018,39(3):324-343
The phase equilibria of the Mg-Pb-Sn ternary system were investigated using a combined method of electron probe microanalyzer and x-ray diffraction. Three isothermal sections of the Mg-Pb-Sn ternary system at 200, 300 and 400 °C were experimentally established. The phase equilibria of Mg-Pb-Sn ternary system were thermodynamically assessed by using CALPHAD (Calculation of Phase Diagrams) method on the basis of the presently determined experimental data. A consistent set of thermodynamic parameters has been derived for describing the Gibbs free energies of each solution phase and intermetallic compound in the Mg-Pb-Sn ternary system. The calculated phase diagrams and thermodynamic properties in the Mg-Pb-Sn ternary system are in good agreement with experimental data. 相似文献
10.
C. Servant 《Journal of Phase Equilibria and Diffusion》2005,26(1):39-49
Thermodynamic assessments have been made for the hafnium-vanadium (Hf-V) and vanadium-zirconium (V-Zr) systems using the Calphad-Thermocalc
approach. The Gibbs energies of the liquid, body-centered cubic, and close-packed hexagonal phases were described by a substitution
solution model with a Redlich-Kister formalism to express the excess Gibbs energy. The C15-Laves phase was treated first as stoichiometric and then with a composition range. A consistent set of optimized thermodynamic
parameters was obtained, and calculated phase equilibria were compared with the experimental data. The enthalpy of formation
of the C15-Laves phase was calculated equal to approximately −3 and −5 kJ/mol, respectively, in the Hf-V and V-Zr systems,
which is in good agreement with predicted values. 相似文献
11.
LIU Xingjun WANG Cuiping WEN Mingzhong CHEN Xing PAN Fusheng 《稀有金属(英文版)》2006,25(5):441-447
The Mg-Al-Zn-Y-Ce system is one of the key systems for designing high-strength Mg alloys. The purpose of the present article is to develop a thermodynamic database for the Mg-Al-Zn-Y-Ce multicomponent system to design Mg alloys using the calculation of phase diagrams (CALPHAD) method, where the Gibbs energies of solution phases such as liquid, fcc, bcc, and hcp phases were described by the subregular solution model, whereas those of all the compounds were described by the sublattice model. The thermodynamic parameters describing Gibbs energies of the different phases in this database were evaluated by fitting the experimental data for phase equilibria and thermodynamic properties. On the basis of this database, a lot of information concerning stable and metastable phase equilibria of isothermal and vertical sections, molar fractions of constituent phases, the liquidus projection, etc., can be predicted. This database is expected to play an important role in the design of Mg alloys. 相似文献
12.
基于Cu-Ni-Sn三元系的相平衡和热力学的实验信息,采用亚正规溶体模型描述液相和fcc相的Gibbs自由能,为了预测该体系中bcc相的A2-B2有序-无序转变,bcc相的Gibbs自由能采用双亚点阵模型进行描述.利用CALPHAD(相图计算)方法评估了Cu-Ni-Sn三元系各相的热力学参数,计算的富Cu侧相图和热力学性质与实验数据比较一致.并对该三元系中bcc相的A2-B2有序-无序转变及fcc相的溶解度间隙进行了计算.这些计算结果对利用析出强化以及Spinodal分解开发高强度和高导电性的新型Cu基合金的组织设计具有一定的指导意义. 相似文献
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Thermodynamic study of phase equilibria in the Pb-Sn-Sb system 总被引:2,自引:0,他引:2
A thermodynamic analysis of the phase equilibria in the Pb-Sn-Sb ternary system was conducted. A regular solution approximation
based on a two-sublattice model was adopted to describe the Gibbs energy of formation of the individual phases in the binary
and ternary systems. In the case of some component binary systems, the effect of pressure also was considered. Experimental
data obtained by differential thermal analysis (DTA) and electron probe microanalysis (EPMA) in the present study, along with
literature data on phase boundaries and thermochemical properties, form the basis for the evaluated thermodynamic parameters
used in the calculation. Calculated and experimental phase boundaries agree fairly well.
Present address: Kawasaki Steel Corporation, Chiba 260, Japan. 相似文献
15.
A thermodynamic database for nuclear materials, including U-Th, U-Pu, Th-Pu, and (U, Th, Pu)-X (X = Al, Co, Cr, Cu, Fe, Ga,
Mg, Mn, Mo, Nb, Ni, Si, Ta, W, Zr) binary system has been developed by the Calculation of Phase Diagrams (CALPHAD) method.
Thermodynamic parameters describing Gibbs free energies of different phases have been evaluated by optimizing experimental
data on phase equilibria and thermodynamic properties. The present thermodynamic database can provide much-needed information
such as stable and metastable phase equilibria, phase fractions, and various thermodynamic quantities that is important to
the design of nuclear materials. This database is also an essential starting point to construct thermodynamic databases for
the multicomponent systems. 相似文献
16.
Phase equilibria in coherent solids differ significantly from equilibria in fluids or incoherent solids. Gibbs' phase rule usually does not apply, the field lines on a phase diagram do not coincide with the equilibrium phase compositions, phase compositions in a two-phase field depend on the bulk alloy composition and, for a given set of imposed thermodynamic variables, several equilibrium states may exist. These conditions place significant constraints on the use of coherent phase diagrams. This paper discusses some aspects of phase equilibria that are unique to coherent systems and how phase information may be conveyed when phase stability diagrams are used in lieu of coherent phase diagrams. The utility of phase stability diagrams lies in their ability to display graphically the equilibrium states of a two-phase coherent system as a function of alloy composition (in much the same way that Gibbs energy vs composition curves show equilibrium states for a fluid system). 相似文献
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C.P. Wang X. Chen X.J. Liu F.S. Pan K. Ishida 《Journal of Alloys and Compounds》2008,458(1-2):166-173
In order to develop the thermodynamic database of phase equilibria in the Mg–Zn–Re (Re: rare earth element) base alloys, the thermodynamic assessments of the Ce–Zn and Pr–Zn systems were carried out by using the calculation of phase diagrams (CALPHAD) method on the basis of the experimental data including thermodynamic properties and phase equilibria. Based on the available experimental data, Gibbs free energies of the solution phases (liquid, bcc, fcc, hcp and dhcp) were modeled by the subregular solution model with the Redlich–Kister formula, and those of the intermetallic compounds were described by the sublattice model. A consistent set of thermodynamic parameters has been derived for describing the Gibbs free energies of each solution phase and intermetallic compound in the Ce–Zn and Pr–Zn binary systems. An agreement between the present calculated results and experimental data is obtained. 相似文献
20.
Taufiq Hidayat Denis Shishin Sergei A. Decterov Evgueni Jak 《Journal of Phase Equilibria and Diffusion》2017,38(4):477-492
Phase equilibria and thermodynamic data in the FeO-Fe2O3-SiO2 system were critically reviewed. New experiments were undertaken to resolve discrepancies found in previous data. The liquid oxide/slag phase was described using the modified quasichemical model. New optimized parameters of the thermodynamic models for the Gibbs energies of slag and other phases in the selected system were obtained. The new parameters reproduce all available phase equilibria and thermodynamic data within the experimental error limits from 298 K (25 °C) to above the liquidus temperatures at all compositions and oxygen partial pressures from metal saturation to 1 atm of O2. This study was carried out as part of the development of a self-consistent thermodynamic database for the Al-Ca-Cu-Fe-Mg-Si-O-S multi-component system. 相似文献