The Experts below are selected from a list of 5988 Experts worldwide ranked by ideXlab platform
Bo Sundman - One of the best experts on this subject based on the ideXlab platform.
-
a thermodynamic description of the al co ni system and site occupancy in co alni3 composite binder phase
Journal of Alloys and Compounds, 2016Co-Authors: Yaru Wang, Bo Sundman, Jianzhan Long, Yingbiao Peng, Peng Zhou, Yong Du, Tao Xu, Zhongjian ZhangAbstract:Abstract Phase equilibria of the Al–Co–Ni system is extremely useful for understanding phase behavior of AlNi3-based L12 phases, regarding its attractive properties, such as high-temperature oxidation resistance and corrosion resistance, high hardness and strength. In the present work, all the experimental data about the phase equilibria and thermodynamic properties of the Al–Co–Ni system were critically evaluated, and a thermodynamic description for this system over the whole composition and temperature ranges was obtained. Most importantly, the ordered/disordered transition between fcc_A1 and L12 phases was described using a four-Sublattice (4SL) Model. Based on the crystallographic and experimental data, three stable ternary intermetallic phases were described using Sublattice Model. Two of them were treated as semi-stoichiometric compounds with homogeneity ranges for Co and Ni, and the other one was treated as a stoichiometric compound. The other phases were described by using substitutional solution Model. The present work provides a more complete and accurate thermodynamic description compared with previous ones. A reasonable agreement was obtained between calculations and experimental data in the ternary system. The occupancy behavior of Co in AlNi3 is thermodynamically predicted, and the computed occupancy shows a much better fit to the experimental data than previous first-principles calculations. In addition, the composition range of the Co + AlNi3 two-phase region, concerning a new type of composite binder for cemented carbides, was found to shift to the Co-rich side with the decrease of the temperature.
-
thermodynamic assessment of the neptunium oxygen system mass spectrometric studies and thermodynamic Modelling
The Journal of Chemical Thermodynamics, 2016Co-Authors: Bo Sundman, A L Smith, J Y Colle, O Benes, R J M Konings, C GueneauAbstract:Abstract Knudsen effusion mass spectrometry measurements on neptunium dioxide are reported in this work, which have allowed to improve the understanding of its vapourization behaviour and solved discrepancies noticed in the literature: the enthalpy of formation of NpO2(g) has been re-assessed and the composition of neptunia at congruent vapourization has been determined at 2262 K. In addition, a thermodynamic Model for the neptunium-oxygen system has been developed using the CALPHAD method. The non stoichiometric NpO2−x phase is described herein using the compound energy formalism with ionic constituents ( Np 3 + , Np 4 + ) 1 ( O 2 - ,Va ) 2 , while the liquid phase is represented with the ionic two-Sublattice Model ( Np 4 + ) P ( O 2 - , Va Q - ,O ) Q . The reliability and consistency of all optimized Gibbs energies have been verified by calculating the phase equilibria, thermodynamic data, oxygen chemical potential and equilibrium partial pressures. Finally, a number of ill-defined data in the Np–O system have been identified after critical review of the literature and comparison with the present experimental results and CALPHAD Model.
-
an assessment of the entire al fe system including d03 ordering
Acta Materialia, 2009Co-Authors: Bo Sundman, Ikuo Ohnuma, N Dupin, Ursula R Kattner, Suzana G FriesAbstract:Abstract The Al–Fe system is important for many alloys and the new interest in iron aluminides makes it necessary to improve the Modeling of the different ordered forms on the body-centered cubic lattice in this system. This has now been done using a four-Sublattice Model based on the compound energy formalism, which can describe disordered A2 and the B2, D 0 3 and B32 ordering. The chemical and ferromagnetic ordering transitions can be both first and second-order and they have a strong interaction. Almost all available experimental and theoretical data for all phases in the system have been fitted within estimated uncertainties.
-
thermodynamic Modelling of the plutonium oxygen system
Journal of Nuclear Materials, 2008Co-Authors: C Gueneau, Christian Chatillon, Bo SundmanAbstract:The published data for the thermodynamic functions and phase equilibria of the plutonium–oxygen system have been examined. Some inconsistencies have been found for oxygen chemical potential and vaporization data of [Pu2O3 + PuO2� x] and PuO2� x domains. As the original chemical potential data were not performed at the same temperature and O/Pu ratio, a chart with fixed temperature and composition ranges was built in order to compare all the experimental data. The discrepancies remain difficult to explain. Thermodynamic Models of all the phases have been derived by the least-squares minimization procedure using the Thermo-Calc software. The compound energy formalism with the Sublattice Models (Pu 3+ ,P u 4+ )1(O 2� , Va)2 and (Pu 3+ ,P u 4+ )2(O 2� )3(O 2� , Va)1 have been chosen to account for the crystal structure, defect chemistry and thermodynamic properties of respectively PuO2� x and PuO1.61 phases. The liquid phase was described using the ionic two-Sublattice Model (Pu 3+ )P(O 2� ,V a Q� , PuO2 ,O ) Q. The reliability of the refined parameters is demonstrated by calculation of the phase diagram, the thermodynamic properties of the phases and the equilibrium partial pressures in the Pu2O3–PuO2 region. Considering the large uncertainties on the experimental information, an overall good agreement was obtained. To improve the thermodynamic description of the system, some missing experimental data are listed.
-
Thermodynamic Modelling of the plutonium–oxygen system
'Elsevier BV', 2008Co-Authors: Guéneau Christine, Chatillon Christian, Bo SundmanAbstract:The published data for the thermodynamic functions and phase equilibria of the plutonium–oxygen system have been examined. Some inconsistencies have been found for oxygen chemical potential and vaporization data of [Pu2O3 + PuO2−x] and PuO2−x domains. As the original chemical potential data were not performed at the same temperature and O/Pu ratio, a chart with fixed temperature and composition ranges was built in order to compare all the experimental data. The discrepancies remain difficult to explain. Thermodynamic Models of all the phases have been derived by the least-squares minimization procedure using the Thermo-Calc software. The compound energy formalism with the Sublattice Models (Pu3+, Pu4+)1(O2−, Va)2 and (Pu3+, Pu4+)2(O2−)3(O2−, Va)1 have been chosen to account for the crystal structure, defect chemistry and thermodynamic properties of respectively PuO2−x and PuO1.61 phases. The liquid phase was described using the ionic two-Sublattice Model (Pu3+)P(O2−, VaQ−, PuO2, O)Q. The reliability of the refined parameters is demonstrated by calculation of the phase diagram, the thermodynamic properties of the phases and the equilibrium partial pressures in the Pu2O3–PuO2 region. Considering the large uncertainties on the experimental information, an overall good agreement was obtained. To improve the thermodynamic description of the system, some missing experimental data are listed
K Ishida - One of the best experts on this subject based on the ideXlab platform.
-
experimental determination and thermodynamic calculation of the phase equilibria in the cu cr nb and cu cr co systems
Journal of Alloys and Compounds, 2009Co-Authors: X J Liu, Zheng Jiang, Cuiping Wang, K IshidaAbstract:Abstract Phase equilibria in the Cu–Cr–Nb and Cu–Cr–Co systems were, respectively, determined by metallography, X-ray diffraction (XRD) and scanning electron microscopy–energy dispersive X-ray (SEM–EDX) techniques. The thermodynamic assessments of the Cu–Cr–Nb and Cu–Cr–Co systems were carried out by using CALPHAD (CALculation of PHAse Diagrams) method on the basis of the experimental data measured by the present and previous works. The Gibbs free energies of the liquid and solid solution phases were described by the subregular solution Model, and those of intermetallic compounds were described by the Sublattice Model. A consistent set of the thermodynamic parameters has been obtained, and the evaluated thermodynamic parameters lead to a better fit between calculated results and experimental data in both the Cu–Cr–Nb and Cu–Cr–Co systems.
-
experimental determination and thermodynamic calculation of phase equilibria in the fe mn al system
Journal of Phase Equilibria and Diffusion, 2006Co-Authors: R Umino, Ikuo Ohnuma, R Kainuma, Cuiping Wang, Xingjun Liu, Yuji Sutou, K IshidaAbstract:The phase equilibria among the face-centered cubic (fcc), body-centered cubic (bcc), and βMn phases at 800, 900, 1000, 1100, and 1200 °C were examined by electron probe microanalysis (EPMA), and the A2/B2 and B2/D03 ordering temperatures were also determined using the diffusion couple method and differential scanning calorimetry (DSC). The critical temperatures for the A2/B2 and B2/D03 ordering were found to increase with increasing Mn content. Thermodynamic assessment of the Fe−Mn−Al system was also undertaken with use of experimental data for the phase equilibria and order-disorder transition temperatures using the CALPHAD (Calculation of Phase Diagrams) method. The Gibbs energies of the liquid, αMn, βMn, fcc, and e phases were described by the subregular solution Model and that of the bcc phase was represented by the two-Sublattice Model. The thermodynamic parameters for describing the phase equilibria and the ordering of the bcc phase were optimized with good agreement between the calculated and experimental results.
-
experimental investigation and thermodynamic calculation of phase equilibria in the sn au ni system
Journal of Electronic Materials, 2005Co-Authors: X J Liu, Ikuo Ohnuma, Yoshikazu Takaku, R Kainuma, M Kinaka, K IshidaAbstract:The phase equilibria of the Sn-Au-Ni system, including six isothermal section diagrams in the Sn-rich portion at 200–600°C, as well as three vertical sections at Au:Ni=1:1, 50at.%Sn, and 40at.%Sn, were investigated by means of differential scanning calorimetry (DSC), x-ray diffraction, and metallography. The experimental results indicated that (1) there exists a ternary compound Sn4AuNi2 that is stable up to about 400°C, (2) there are larger solubilities of Au in the Ni3Sn2 phase in the Sn-Ni system and Ni in the SnAu phase in the Sn-Au system, and (3) there is the two-phase equilibrium between Sn2Ni3 and SnAu compounds below 400°C, rather than the continuous phase region from the Sn2Ni3 to the SnAu phases reported previously. Thermodynamic assessment of the Sn-Au-Ni system was also carried out by using the calculation of phase diagrams (CALPHAD) method, in which the Gibbs energies of the liquid, fcc, and hcp phases are described by the subregular solution Model and that of compounds, including a ternary compound, are represented by the Sublattice Model. The thermodynamic parameters for describing each phase were optimized and good agreement between the calculated and experimental results was obtained.
-
Experimental investigation and thermodynamic calculation of the phase equilibria in the Cu-Sn and Cu-Sn-Mn systems
Metallurgical and Materials Transactions A, 2004Co-Authors: X J Liu, R Kainuma, I Ohnuma, C. P. Wang, K IshidaAbstract:The phase equilibria in the Cu-rich portion of the Cu-Sn binary and Cu-Sn-Mn ternary systems have been determined using the diffusion-couple method, differential scanning calorimetry (DSC), high-temperature electron diffraction (HTED), and high-temperature X-ray diffraction (HTXRD) techniques. The present experimental results on the binary Cu-Sn system show the presence of the two-stage, second-order reaction A2 → B2 → D0_3 in the bcc-phase region, rather than a two-phase equilibrium between the disordered bcc (A2) and the ordered bcc (D0_3) phases, as reported before. Phase equilibria in the Cu-Sn-Mn ternary system in the composition range of 0 to 30 at. pct Sn and 0 to 30 at. pct Mn at 550 °C, 600 °C, 650 °C, and 700 °C have been determined, and a ternary compound (Cu_4MnSn) with a very small solubility has been detected. A thermodynamic analysis of the Cu-Sn-Mn ternary system including the Cu-Sn and Mn-Sn binary systems has also been carried out by the CALPHAD (Calculation of Phase Diagrams) method, in which the Gibbs energy of the bcc phase is described by the two-Sublattice Model in order to take into account the second-order A2/B2 ordering reaction. A consistent set of optimized thermodynamic parameters for the Cu-Sn-Mn system for describing the Gibbs energy of each phase results in a better fit between calculation and experiment.
-
experimental determination and thermodynamic calculation of the phase equilibria in the cu in sn system
Journal of Electronic Materials, 2001Co-Authors: X J Liu, Ikuo Ohnuma, R Kainuma, K Ishida, H S Liu, S Itabashi, K Kameda, Katsunori YamaguchiAbstract:The phase equilibria of the Cu-In-Sn system were investigated by means of the diffusion couple method, differential scanning calorimetry (DSC) and metallography. The isothermal sections at 110–900 C, as well as vertical sections at 10wt.%Cu–70wt.%Cu were determined. It was found that there are large solubilities of In in the e(Cu3Sn), δ(Cu41Sn11), and η phases in the Cu-Sn system, and large solubilities of Sn in the γ, η, and δ(Cu7In3) phases in the Cu-In system. The η phase was found to continuously form from the Cu-In side to the Cu-Sn side, and a ternary compound (Cu2In3Sn) was found to exist at 110 C. Thermodynamic assessment of the Cu-In-Sn system was also carried out based on experimental data of activity and phase equilibria using the CALPHAD method, in which the Gibbs energies of the liquid, fcc and bcc phases are described by the subregular solution Model and that of compounds, including two ternary compounds, are represented by the Sublattice Model. The thermodynamic parameters for describing the phase equilibria were optimized, and agreement between the calculated and experimental results was obtained.
Jicheng Zhao - One of the best experts on this subject based on the ideXlab platform.
-
experimental determination of the ni cr ru phase diagram and thermodynamic reassessments of the cr ru and ni cr ru systems
Intermetallics, 2015Co-Authors: L L Zhu, Liang Jiang, Z P Jin, Jicheng ZhaoAbstract:Abstract Ruthenium addition was found to be beneficial in inhibiting the formation of the detrimental topologically closed-packed (TCP) phases in Ni-based single crystal superalloys; thus, the Ni–Cr–Ru phase stability is very valuable for better understanding of the constitutional effects of Ru in multicomponent Ni-base superalloys. Four isothermal sections of the Ni–Cr–Ru system at 800 °C, 900 °C, 1000 °C and 1200 °C were constructed from results obtained from diffusion multiples using scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). The measured phase equilibria together with prior experimental results were used to optimize a CALPHAD thermodynamic description of the Ni–Cr–Ru ternary system using thermodynamic parameters of the Ni–Cr and Ni–Ru systems published in the literature and modified Cr–Ru parameters from the current study. The intermetallic compound sigma phase in the Cr–Ru system was described with a simplified two-Sublattice Model, (Cr,Ru) 20 (Cr,Ru) 10 , by taking into account future extension of the Model into higher order systems. Comparison between the calculated results and the experimental measurements was made to demonstrate the reliability of the current thermodynamic parameters for the Ni–Cr–Ru system. For easy implementation of the thermodynamic parameters into some existing thermodynamic databases, a version of the thermodynamic description of the Ni–Cr–Ru system with an older Sublattice Model, (Cr,Ni,Ru) 10 (Cr) 4 (Cr,Ni,Ru) 16 , for the sigma phase was also developed.
Zikui Liu - One of the best experts on this subject based on the ideXlab platform.
-
thermodynamic reassessment of the ni si ti system using a four Sublattice Model for ordered disordered fcc phases supported by first principles calculations
Journal of Alloys and Compounds, 2017Co-Authors: Xiaoming Yuan, Jiong Wang, Zikui LiuAbstract:Abstract A thermodynamic reassessment of the ternary Ni–Si–Ti system was performed by means of CALPHAD (CALculation of PHAse Diagram) method. The fcc_A1/Ni 3 Si-L1 2 disordered/ordered transition was described using a four-Sublattice Model. The enthalpies of formation of the ternary compounds τ 1 , τ 2 , and τ 4 and end-members of the Ti 5 Si 3 and Ni 3 Ti phases at 0 K in the Ni–Si–Ti ternary system were computed via first-principles calculations to supply necessary thermodynamic data for the CALPHAD Modeling. In the Ni–Si–Ti ternary system, it was clarified that the ordered Ni 3 Si-L1 2 phase is formed from the liquid phase with the addition of Ti. An optimal set of thermodynamic parameters for the Ni–Si–Ti system was obtained by taking into consideration of the experimental data from the literature and theoretic values from the present first-principles calculations. Comparisons between the calculated and measured phase diagrams indicated that almost all the reliable experimental information was satisfactorily accounted for by the present Modeling.
-
experimental investigation and thermodynamic Modeling of the cu si zn system with the refined description for the cu zn system
Calphad-computer Coupling of Phase Diagrams and Thermochemistry, 2011Co-Authors: Peisheng Wang, Jiong Wang, Shunli Shang, Lijun Zhang, Wenqing Zhang, Shuhong Liu, Zikui LiuAbstract:Abstract The isothermal section of the Cu–Si–Zn ternary system at 600 °C was experimentally determined with fifteen alloys by means of optical microscopy, X-ray diffraction, and the scanning electron microscopy with energy dispersive X-ray spectroscopy. At 600 °C, no ternary compounds were observed, and five three-phase equilibria were well determined. In particular, the longstanding controversy regarding the four three-phase equilibria in the Cu-rich corner involving the phases α , β , γ - Cu5Zn8, and κ - Cu7Si was resolved experimentally in the present work. In an effort to provide a compatible thermodynamic description of the Cu–Si–Zn system for the multi-component Al-based thermodynamic database, the Cu–Zn system was reModeled using the CALPHAD approach with a new Sublattice Model Zn4(Cu,Zn)1(Cu,Zn)8 for the γ - Cu5Zn8 phase. Besides, the temperature dependence of enthalpy of mixing was also taken into account for the liquid phase. Subsequently, a thermodynamic description of the Cu–Si–Zn system was obtained over the entire composition range based on the presently Modeled Cu–Zn system and the experimental data from the literature and the present measurements. It is found that most reliable experimental data in this ternary system are satisfactorily reproduced by the present thermodynamic Modeling.
-
b2 phases and their defect structures part i ab initio enthalpy of formation and enthalpy of mixing in the al ni pt ru system
MRS Proceedings, 2004Co-Authors: Sara Prins, Raymundo Arroyave, Chao Jiang, Zikui LiuAbstract:The enthalpies of formation of the bcc phases in the Al-Ni-Pt-Ru system, particularly in the Al-Ru binary and Pt-Al-Ru ternary subsystems, were calculated by first principle methods. The enthalpies of formation for stoichiometric bcc-B2 phases have been calculated using both the GGA and LDA approximations, while the enthalpies of formation for B2 phases with large amounts of constitutional defects (both vacancies and anti-site atoms) were calculated using the Special Quasirandom Structures (SQS) approach. The enthalpies of mixing for the disordered bcc-A2 phases have also been calculated with SQS by mimicking the random bcc alloy with the local pair and multisite correlation functions. The calculated B2 lattice parameters for the different defect structures were compared with experimental results. These results are used as input values for the CALPHAD modified Sublattice Model to describe the A2/B2 phases with one Gibbs energy function.
X J Liu - One of the best experts on this subject based on the ideXlab platform.
-
experimental determination and thermodynamic calculation of the phase equilibria in the cu cr nb and cu cr co systems
Journal of Alloys and Compounds, 2009Co-Authors: X J Liu, Zheng Jiang, Cuiping Wang, K IshidaAbstract:Abstract Phase equilibria in the Cu–Cr–Nb and Cu–Cr–Co systems were, respectively, determined by metallography, X-ray diffraction (XRD) and scanning electron microscopy–energy dispersive X-ray (SEM–EDX) techniques. The thermodynamic assessments of the Cu–Cr–Nb and Cu–Cr–Co systems were carried out by using CALPHAD (CALculation of PHAse Diagrams) method on the basis of the experimental data measured by the present and previous works. The Gibbs free energies of the liquid and solid solution phases were described by the subregular solution Model, and those of intermetallic compounds were described by the Sublattice Model. A consistent set of the thermodynamic parameters has been obtained, and the evaluated thermodynamic parameters lead to a better fit between calculated results and experimental data in both the Cu–Cr–Nb and Cu–Cr–Co systems.
-
experimental investigation and thermodynamic calculation of phase equilibria in the sn au ni system
Journal of Electronic Materials, 2005Co-Authors: X J Liu, Ikuo Ohnuma, Yoshikazu Takaku, R Kainuma, M Kinaka, K IshidaAbstract:The phase equilibria of the Sn-Au-Ni system, including six isothermal section diagrams in the Sn-rich portion at 200–600°C, as well as three vertical sections at Au:Ni=1:1, 50at.%Sn, and 40at.%Sn, were investigated by means of differential scanning calorimetry (DSC), x-ray diffraction, and metallography. The experimental results indicated that (1) there exists a ternary compound Sn4AuNi2 that is stable up to about 400°C, (2) there are larger solubilities of Au in the Ni3Sn2 phase in the Sn-Ni system and Ni in the SnAu phase in the Sn-Au system, and (3) there is the two-phase equilibrium between Sn2Ni3 and SnAu compounds below 400°C, rather than the continuous phase region from the Sn2Ni3 to the SnAu phases reported previously. Thermodynamic assessment of the Sn-Au-Ni system was also carried out by using the calculation of phase diagrams (CALPHAD) method, in which the Gibbs energies of the liquid, fcc, and hcp phases are described by the subregular solution Model and that of compounds, including a ternary compound, are represented by the Sublattice Model. The thermodynamic parameters for describing each phase were optimized and good agreement between the calculated and experimental results was obtained.
-
Experimental investigation and thermodynamic calculation of the phase equilibria in the Cu-Sn and Cu-Sn-Mn systems
Metallurgical and Materials Transactions A, 2004Co-Authors: X J Liu, R Kainuma, I Ohnuma, C. P. Wang, K IshidaAbstract:The phase equilibria in the Cu-rich portion of the Cu-Sn binary and Cu-Sn-Mn ternary systems have been determined using the diffusion-couple method, differential scanning calorimetry (DSC), high-temperature electron diffraction (HTED), and high-temperature X-ray diffraction (HTXRD) techniques. The present experimental results on the binary Cu-Sn system show the presence of the two-stage, second-order reaction A2 → B2 → D0_3 in the bcc-phase region, rather than a two-phase equilibrium between the disordered bcc (A2) and the ordered bcc (D0_3) phases, as reported before. Phase equilibria in the Cu-Sn-Mn ternary system in the composition range of 0 to 30 at. pct Sn and 0 to 30 at. pct Mn at 550 °C, 600 °C, 650 °C, and 700 °C have been determined, and a ternary compound (Cu_4MnSn) with a very small solubility has been detected. A thermodynamic analysis of the Cu-Sn-Mn ternary system including the Cu-Sn and Mn-Sn binary systems has also been carried out by the CALPHAD (Calculation of Phase Diagrams) method, in which the Gibbs energy of the bcc phase is described by the two-Sublattice Model in order to take into account the second-order A2/B2 ordering reaction. A consistent set of optimized thermodynamic parameters for the Cu-Sn-Mn system for describing the Gibbs energy of each phase results in a better fit between calculation and experiment.
-
experimental determination and thermodynamic calculation of the phase equilibria and surface tension in the sn ag in system
Journal of Electronic Materials, 2002Co-Authors: X J Liu, Ikuo Ohnuma, Kiyohito Ishida, Y Inohana, Yoshikazu Takaku, R Kainuma, Z Moser, W Gasior, Janusz PstrusAbstract:The phase equilibria of the Sn-Ag-In system were investigated by means of differential scanning calorimetry (DSC) and metallography. The isothermal sections at 180–600°C, as well as some vertical sections, were determined. Thermodynamic assessment of this system was also carried out based on the experimental data of thermodynamic properties and phase equilibria using the calculation of phase diagram (CALPHAD) method, in which the Gibbs energies of the liquid, fcc, and hcp phases are described by the subregular solution Model, and those of compounds are represented by the Sublattice Model. The thermodynamic parameters for describing the phase equilibria were optimized, and reasonable agreement between the calculated and experimental results was obtained. The maximum bubble-pressure method and dilatometric method have been used in measurements of the surface tension and density of the binary In-Sn and ternary (Sn-3.8Ag)eut + In (5 at.% and 10 at.%) liquid alloys, respectively. The experiments were performed in the temperature range from 160–930°C. The experimental data of the surface tension were compared with those obtained by the thermodynamic calculation of Butler’s Model.
-
experimental determination and thermodynamic calculation of the phase equilibria in the cu in sn system
Journal of Electronic Materials, 2001Co-Authors: X J Liu, Ikuo Ohnuma, R Kainuma, K Ishida, H S Liu, S Itabashi, K Kameda, Katsunori YamaguchiAbstract:The phase equilibria of the Cu-In-Sn system were investigated by means of the diffusion couple method, differential scanning calorimetry (DSC) and metallography. The isothermal sections at 110–900 C, as well as vertical sections at 10wt.%Cu–70wt.%Cu were determined. It was found that there are large solubilities of In in the e(Cu3Sn), δ(Cu41Sn11), and η phases in the Cu-Sn system, and large solubilities of Sn in the γ, η, and δ(Cu7In3) phases in the Cu-In system. The η phase was found to continuously form from the Cu-In side to the Cu-Sn side, and a ternary compound (Cu2In3Sn) was found to exist at 110 C. Thermodynamic assessment of the Cu-In-Sn system was also carried out based on experimental data of activity and phase equilibria using the CALPHAD method, in which the Gibbs energies of the liquid, fcc and bcc phases are described by the subregular solution Model and that of compounds, including two ternary compounds, are represented by the Sublattice Model. The thermodynamic parameters for describing the phase equilibria were optimized, and agreement between the calculated and experimental results was obtained.
