scholarly journals Essential Magnesium Alloys Binary Phase Diagrams and Their Thermochemical Data

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.

2005 ◽  
Vol 41 (1) ◽  
pp. 79-93 ◽  
Author(s):  
G. Vassilev

Systematic discussion of the binary phase diagrams formed by low-melting elements (Bi, Sn, Zn, In) and the metallic elements of IV-th and V-th periods has been done. Some options for theoretical prediction of the type of the phase diagrams relying on general criteria (enthalpy of formation, assessed by the Miedema model, and size factor) have been applied, and compared with experimental data about the respective binary systems. The systematization helps to determine the scope and the limits of such an approach. These predictions have been compared with experimental data about the respective binary systems studied by the author. Forecasts for the general features of some unknown binary systems have been deduced.


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.


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.


2002 ◽  
Vol 74 (10) ◽  
pp. 1871-1884 ◽  
Author(s):  
V. M. Valyashko

Four main types of binary fluid-phase diagrams and available experimental data on binary systems are used as a starting point for derivation of the systematic classification of binary complete phase diagrams by the method of continuous topological transformations. This method and the classification of binary phase diagrams, containing the boundary versions of phase diagrams with ternary nonvariant points, are applied to derive the main types of fluid and complete phase diagrams for ternary systems with one volatile component and immiscibility phenomena in two constituent binary subsystems. The results gained from this analysis of derived fluid and complete phase diagrams of ternary systems are represented.


2014 ◽  
Vol 50 (2) ◽  
pp. 139-144 ◽  
Author(s):  
Q. Shu ◽  
L. Wang ◽  
K.C. Chou

A new method, combining KTH model with geometrical model (General solution model by Chou) to estimate viscosity of some ternary silicate slags, was proposed in this work. According to modified KTH model, viscous Gibbs free energy for mixing of ternary slags was estimated by employing general solution model. It was found that viscous Gibbs energy for mixing of ternary system could be calculated using solely viscous Gibbs energy for mixing of sub-binary systems. The viscosities of five ternary slags CaO-MnO-SiO2, CaO-FeO-SiO2, FeO-MnO-SiO2, CaO-MgO-SiO2 and FeO-MgO-SiO2 were estimated in the present work. A good agreement with available experimental data, with mean deviation less than 20%, was achieved. The modified KTH model has advantages with less model parameters and improved estimation ability by comparison to original KTH model.


2014 ◽  
Vol 790-791 ◽  
pp. 265-270
Author(s):  
Eszter Tatárka ◽  
Tamás Mende ◽  
András Roósz

This paper includes the binary and ternary liquidus temperature calculations of Sn-Bi-Cd system. The calculation was performed in cases of the surfaces of Sn, Bi and Cd phases too. First of all the liquidus curves were calculated in the binary systems (Bi phase in Bi-Cd and Bi-Sn systems, Sn phase in Sn-Cd and Sn-Bi systems, Cd phase in Cd-Sn and Cd-Bi systems). By using the calculated coefficients of the binary phase diagrams and the data from the digitalized ternary phase diagram, the liquidus temperature of Sn, Bi and the Cd phases were calculated. Finally the eutectic point of the binary liquidus curves and the eutectic valley of the Sn and the Bi surfaces were calculated by means of an iteration method.


1992 ◽  
Vol 23 (2) ◽  
pp. 89-104 ◽  
Author(s):  
Ole H. Jacobsen ◽  
Feike J. Leij ◽  
Martinus Th. van Genuchten

Breakthrough curves of Cl and 3H2O were obtained during steady unsaturated flow in five lysimeters containing an undisturbed coarse sand (Orthic Haplohumod). The experimental data were analyzed in terms of the classical two-parameter convection-dispersion equation and a four-parameter two-region type physical nonequilibrium solute transport model. Model parameters were obtained by both curve fitting and time moment analysis. The four-parameter model provided a much better fit to the data for three soil columns, but performed only slightly better for the two remaining columns. The retardation factor for Cl was about 10 % less than for 3H2O, indicating some anion exclusion. For the four-parameter model the average immobile water fraction was 0.14 and the Peclet numbers of the mobile region varied between 50 and 200. Time moments analysis proved to be a useful tool for quantifying the break through curve (BTC) although the moments were found to be sensitive to experimental scattering in the measured data at larger times. Also, fitted parameters described the experimental data better than moment generated parameter values.


Author(s):  
Afshin Anssari-Benam ◽  
Andrea Bucchi ◽  
Giuseppe Saccomandi

AbstractThe application of a newly proposed generalised neo-Hookean strain energy function to the inflation of incompressible rubber-like spherical and cylindrical shells is demonstrated in this paper. The pressure ($P$ P ) – inflation ($\lambda $ λ or $v$ v ) relationships are derived and presented for four shells: thin- and thick-walled spherical balloons, and thin- and thick-walled cylindrical tubes. Characteristics of the inflation curves predicted by the model for the four considered shells are analysed and the critical values of the model parameters for exhibiting the limit-point instability are established. The application of the model to extant experimental datasets procured from studies across 19th to 21st century will be demonstrated, showing favourable agreement between the model and the experimental data. The capability of the model to capture the two characteristic instability phenomena in the inflation of rubber-like materials, namely the limit-point and inflation-jump instabilities, will be made evident from both the theoretical analysis and curve-fitting approaches presented in this study. A comparison with the predictions of the Gent model for the considered data is also demonstrated and is shown that our presented model provides improved fits. Given the simplicity of the model, its ability to fit a wide range of experimental data and capture both limit-point and inflation-jump instabilities, we propose the application of our model to the inflation of rubber-like materials.


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.


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