Thermodynamic Database of the Phase Diagrams in the Au-RE Binary Systems

2016 ◽  
Vol 850 ◽  
pp. 433-438 ◽  
Author(s):  
Yu Heng Li ◽  
Fei Xu ◽  
Peng Wu Yang ◽  
Jia Lian Li ◽  
Lu Jiang Zhou ◽  
...  

The thermodynamic database has been developed for Au-RE binary systems. Based on the experimental data including thermodynamic properties and phase equilibrium, the thermodynamic assessments of phase diagrams in the Au-RE (RE: Nd, Dy, Yb, Gd, Tb, Sm, Lu) binary systems were carried out by using the CALPHAD (Calculation of Phase Diagrams) method. The Gibbs free energies of the solution phases were described by substitutional solution model, and all of the intermetallic compounds were described by sublattice models. The calculated phase diagrams are congruent with the available experimental data. Combined with the assessed Au-RE (RE: La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) binary systems, the thermodynamic database of Au-RE binary systems has been developed, and some significant information of thermodynamic properties and phase equilibrium could be calculated, which is important for the further development of Sn-Au-RE high-temperature lead-free solders.

2016 ◽  
Vol 850 ◽  
pp. 439-443 ◽  
Author(s):  
Jia Lian Li ◽  
Shu Liang Wang ◽  
Xue Qin ◽  
Yu Heng Li ◽  
Lu Jiang Zhou ◽  
...  

Sc-based alloys have been used as aero-structures materials, and Sc addition on wrought alloys has positive effects on weldability and welding properties. Phase diagrams play an effective role during the development of new type of alloy with good properties. Therefore, to establish the thermodynamic database of Sc-X binary systems is important and necessary.In the present work, the thermodynamic assessments of Sc-X (Ag, B, Cr, Er, Gd, Mo, Th, W, Y, Zr) binary systems was carried out by using CALPHAD (Calculation of Phase Diagrams) method based on the experimental data including thermodynamic properties and phase equilibria. The Gibbs free energies of the solution phases were described by the sub-regular solution model with the Redlich-Kister equation, and those of the intermetallic compounds were described by the sub-lattice model. A set of self-consistent thermodynamic parameters were derived for describing the Gibbs free energies of each solution phase and intermetallic compound. The calculated phase diagrams and thermodynamic properties are in good agreement with experimental data. The thermodynamic database of the Sc-X (Al, Ag, B, Ca, Co, Cr, Cu, Er, Fe, Ga, Gd, Ge, La, Li, Mg, Mn, Mo, Ni, Pb, Pd, Ru, Sn, Th, W, Y, Zn, Zr) binary systems have been developed, which can provide much important thermodynamic information for multicomponent Al-Sc based alloys.


2015 ◽  
Vol 814 ◽  
pp. 313-318 ◽  
Author(s):  
Jia Lian Li ◽  
Shu Liang Wang ◽  
Lu Jiang Zhou ◽  
Xiao Hong Wang ◽  
Yuan Hua Lin ◽  
...  

The addition of the rare earth elements into the Ag-based filler alloy, which is typical and important, can control and eliminate the negative effect of impurity elements, and furthermore, it improves the spreading property of the Ag-based filler alloy. Phase diagram provides an important direction for materials design of the Ag-based filler alloy. Thus it is necessary to investigate the phase diagrams and construct the thermodynamic database. On the basis of this background, thermodynamic assessments of the Au-Gd, Tb binary systems were carried out by using the CALPHAD (Calculation of Phase Diagrams) method based on the experimental data including thermodynamic properties and phase equilibrium. The Gibbs free energies of the solution phases were described by sub-regular solution models with the Redlich-Kister equation, while all of the intermetallic compounds were described by sub-lattice models. A consistent set of thermodynamic parameters was derived from describing the Gibbs free energies of each solution phase and intermetallic compound. The calculated phase diagram achieved consistency with the available experiments. Then combined with the assessed relevant binary systems, the Ag-Au-Gd, Tb ternary systems have been predicted. The thermodynamic database of these ternary systems has been developed to present the significant information for the design of Ag-based filler alloys.


1984 ◽  
Vol 62 (3) ◽  
pp. 457-474 ◽  
Author(s):  
A. D. Pelton ◽  
C. W. Bale ◽  
P. L. Lin

Phase diagrams and thermodynamic properties of five additive molten salt ternary systems and nine reciprocal molten salt ternary systems containing the ions Li+, Na+, [Formula: see text], OH− are calculated from the thermodynamic properties of their binary subsystems which were obtained previously by a critical assessment of the thermodynamic data and the phase diagrams in these binary systems. Thermodynamic properties of ternary liquid phases are estimated from the binary properties by means of the Conformal Ionic Solution Theory. The ternary phase diagrams are then calculated from these thermodynamic properties by means of computer programs designed for the purpose. It is found that a ternary phase diagram can generally be calculated in this way with a maximum error about twice that of the maximum error in the binary phase diagrams upon which the calculations are based. If, in addition, some reliable ternary phase diagram measurements are available, these can be used to obtain small ternary correction terms. In this way, ternary phase diagram measurements can be smoothed and the isotherms drawn in a thermodynamically correct way. The thermodynamic approach permits experimental data to be critically assessed in the light of thermodynamic principles and accepted solution models. A critical assessment of error limits on all the calculated ternary diagrams is made, and suggestions as to which composition regions merit further experimental study are given.


2011 ◽  
Vol 9 (1) ◽  
pp. 149-156 ◽  
Author(s):  
Nikolina Milcheva ◽  
Jolanta Romanowska ◽  
Gueorgui Vassilev

AbstractExperimental data of bismuth activity coefficients at 1773 K were obtained by isopiestic method and compared to calculated values. Thermodynamic properties of the Sn-Ni-Bi liquid phase were estimated by means of the general solution model and by the methods of Kohler. Description of the ternary liquid phase (Gibbs excess energy dependence on the temperature and the composition) was achieved by using available thermodynamic data of the constitutive binary systems (Ni-Bi, Sn-Bi, Sn-Ni). A comparison between calculated quantities and experimental data wasconducted. The present assessment with thermodynamically optimized values of the system Sn-Ni-Bi (obtained by the CALPHAD approach) was in good agreement. The suggested appearance of a liquid phase miscibility gap at high temperatures is in agreement with the experimental bismuth activity data and with the assessed thermochemical functions.


2002 ◽  
Vol 755 ◽  
Author(s):  
Shihuai Zhou ◽  
Long-Qing Chen ◽  
Rebecca A. MacKay ◽  
Zi-Kui Li u

ABSTRACTThe phase equilibria and thermodynamic properties of the ternary Ni-Al-Ta system on Ni-rich side were analyzed. Thermodynamic descriptions of the liquid, γ-fcc, γ'-L12, and π-Ni6AlTa phases were obtained using the CALPHAD (CALculation of PHase Diagrams) technique. The thermodynamics of γ-fcc and γ'-L12 phases were modeled with a single Gibbs energy function taking into account the crystallographic relation between the two phases. The ternary interaction parameters of the liquid and fcc phases were also determined. The calculated phase diagrams of the ternary Ni-Al-Ta system show a good agreement with experimental data.


2007 ◽  
Vol 263 ◽  
pp. 99-104 ◽  
Author(s):  
A. Kroupa ◽  
J. Vízdal

The methods for the modeling of thermodynamic properties of multicomponent systems are described here. The rules for the creation of a consistent database for multicomponent systems are described generally and documented on the Thermodynamic Database for Lead-free Solders developed in the scope of COST 531 Action. The reassessment of the Sb-Sn system is shown as an example, illustrating the application of consistency rules.


2014 ◽  
Vol 2014 ◽  
pp. 1-33 ◽  
Author(s):  
Mohammad Mezbahul-Islam ◽  
Ahmad Omar Mostafa ◽  
Mamoun Medraj

Magnesium-based alloys are becoming a major industrial material for structural applications because of their potential weight saving characteristics. All the commercial Mg alloys like AZ, AM, AE, EZ, ZK, and so forth series are multicomponent and hence it is important to understand the phase relations of the alloying elements with Mg. In this work, eleven essential Mg-based binary systems including Mg-Al/Zn/Mn/Ca/Sr/Y/Ni/Ce/Nd/Cu/Sn have been reviewed. Each of these systems has been discussed critically on the aspects of phase diagram and thermodynamic properties. All the available experimental data has been summarized and critically assessed to provide detailed understanding of the systems. The phase diagrams are calculated based on the most up-to-date optimized parameters. The thermodynamic model parameters for all the systems except Mg-Nd have been summarized in tables. The crystallographic information of the intermetallic compounds of different binary systems is provided. Also, the heat of formation of the intermetallic compounds obtained from experimental, first principle calculations and CALPHAD optimizations are provided. In addition, reoptimization of the Mg-Y system has been done in this work since new experimental data showed wider solubility of the intermetallic compounds.


2012 ◽  
Vol 549 ◽  
pp. 122-125
Author(s):  
Li Juan Yang ◽  
Dong Liang Shen ◽  
Shi Qiang Wang ◽  
Ya Fei Guo ◽  
Tian Long Deng

It is well known that the exploitation of brine resources of salt lakes is based on the relevant phase equilibrium and phase diagrams. In this paper, the progresses on the stable and metastable equilibria, thermodynamic properties and predictive solubilities of the brine system containing lithium and borate ions at present were summarized. The problems existed and the new trends in the future were also carried out.


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