scholarly journals Thermodynamic modeling of the Na-X (X = Si, Ag, Cu, Cr) systems

2012 ◽  
Vol 48 (2) ◽  
pp. 273-282 ◽  
Author(s):  
D. Hao ◽  
M. Bu ◽  
Y. Wang ◽  
Y. Tang ◽  
Q. Gao ◽  
...  
Keyword(s):  
Low Temperature ◽  
Thermodynamic Modeling ◽  
First Principles ◽  
Binary Systems ◽  
Experimental Information ◽  
Enthalpies Of Formation ◽  
Calphad Approach ◽  
First Principles Calculations ◽  
Self Consistent ◽  
Measured Phase

The Na-X (X = Si, Ag, Cu, Cr) systems have been critically reviewed and modeled by means of the CALPHAD approach. The two compounds, NaSi and Ag2Na, are treated as stoichiometric ones. By means of first-principles calculations, the enthalpies of formation at 0 K for the LT-NaSi (low temperature form of NaSi) and Ag2Na have been computed to be -5210 and -29821.8 Jmol-1, respectively, with the desire to assist thermodynamic modeling. One set of self-consistent thermodynamic parameters is obtained for each of these binary systems. Comparisons between calculated and measured phase diagrams show that most of the experimental information can be satisfactorily accounted for by the present thermodynamic descriptions.

scholarly journals Thermodynamic modeling of the Bi-M (M = Ti, Cr, V) systems

2013 ◽  
Vol 49 (3) ◽  
pp. 307-313 ◽  
Author(s):  
Z. Cao ◽  
J. Xin ◽  
C. Chen ◽  
S. Liu ◽  
B. Hu ◽  
...  
Keyword(s):  
Thermodynamic Modeling ◽  
First Principles ◽  
Binary Systems ◽  
Ideal Gas ◽  
First Principles Calculations ◽  
Calphad Technique ◽  
Gas Phases ◽  
Self Consistent ◽  
The Enthalpy Of Formation ◽  
Measured Phase

The Bi-M (M = Ti, Cr, V) systems have been critically reviewed and modeled by means of the CALPHAD technique. All the intermetallics (BiTi3, BiTi2, Bi9Ti8, Bi3Ti2 and Bi2Ti) were treated as stoichiometric compounds. The enthalpy of formation at 0 K for BiTi2 was computed via first-principles calculations to assist the thermodynamic modeling. The gas phases for the Bi-Cr and Bi-V systems were treated as ideal gas. A set of self-consistent thermodynamic parameters has been finally obtained for each of these binary systems. Comparisons between the calculated and measured phase diagrams as well as first-principles calculations show that most of experimental data can be satisfactorily reproduced by the present thermodynamic descriptions.

scholarly journals Thermodynamic modeling of the In-Sc and In-Y systems supported by first-principles calculations

2018 ◽  
Vol 54 (2) ◽  
pp. 161-167 ◽  
Author(s):  
Z. Hu ◽  
C. Huang ◽  
J. Tu ◽  
Y. Huang ◽  
A. Dong
Keyword(s):  
Intermetallic Compounds ◽  
Thermodynamic Modeling ◽  
First Principles ◽  
Regular Solution Model ◽  
Calphad Method ◽  
Enthalpies Of Formation ◽  
Thermodynamic Optimization ◽  
First Principles Calculations ◽  
Self Consistent ◽  
Good Agreement

Based on an assessment of the phase equilibria and thermodynamic data in the literature, the thermodynamic modeling of the In?Sc and In?Y systems was carried out by means of the calculation of phase diagram (CALPHAD) method supported by first-principles calculations. The solution phases, i.e., liquid, (In), (?Sc), (?Sc), (?Y) and (?Y), were modeled with the substitutional regular solution model. Ten intermetallic compounds, including InSc3, InSc2, In4Sc5, InSc, In2Sc, In3Sc, InY2, InY, In5Y3, and In3Y were described as stoichiometric phases, while In3Y5 was modeled with a sublattice model with respect to its homogeneity range. The enthalpies of formation of the intermetallic compounds at 0 K were computed using firstprinciple calculations and were used as input for the thermodynamic optimization. A set of self-consistent thermodynamic parameters for both the In?Sc and In?Y systems were obtained and the calculated phase diagrams are in good agreement with the experimental data.

scholarly journals Thermodynamic modeling of the Sc-Zn system coupled with first-principles calculation

2012 ◽  
Vol 48 (1) ◽  
pp. 123-130 ◽  
Author(s):  
C. Tang ◽  
P. Zhou ◽  
D.D. Zhao ◽  
X.M. Yuan ◽  
Y. Tang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Phase Diagram ◽  
Thermodynamic Modeling ◽  
First Principles ◽  
Calculated Phase Diagram ◽  
First Principles Calculation ◽  
Enthalpies Of Formation ◽  
First Principles Calculations ◽  
Self Consistent ◽  
Diagram Approach

The Sc-Zn system has been critically reviewed and assessed by means of CALPHAD (CALculation of PHAse Diagram) approach. By means of first-principles calculation, the enthalpies of formation at 0 K for the ScZn, ScZn2, Sc17Zn58, Sc3Zn17 and ScZn12 have been computed with the desire to assist thermodynamic modeling. A set of self-consistent thermodynamic parameters for the Sc-Zn system is then obtained. The calculated phase diagram and thermodynamic properties agree well with the experimental data and first-principles calculations, respectively.

scholarly journals Thermodynamic assessment of the Pb-Sr system

2017 ◽  
Vol 53 (3) ◽  
pp. 179-187 ◽  
Author(s):  
H. Zhang ◽  
C. Zhang ◽  
W.W. Wang ◽  
Y. Du ◽  
P. Zhou ◽  
...  
Keyword(s):  
First Principles ◽  
Thermodynamic Assessment ◽  
Thermodynamic Description ◽  
Experimental Information ◽  
Enthalpies Of Formation ◽  
First Principles Calculations ◽  
Exponential Polynomials ◽  
Self Consistent ◽  
Five Phases ◽  
Measured Phase Diagram

The Pb-Sr system has been critically reviewed and modeled by means of the CALPHAD (CALculation of PHAse Diagrams) approach. It contains seven stoichiometric compounds, i.e. SrPb3, Sr3Pb5, Sr2Pb3, SrPb, Sr5Pb4, Sr5Pb3 and Sr2Pb, in which the SrPb3 and Sr2Pb phases melt congruently, and the other five phases form via peritectic reactions. The enthalpies of formation for the intermetallic compounds at 0 K are provided by first-principles calculations. The liquid, fcc and bcc phases are modeled as substitutional solution phases. Both Redlich-Kister and exponential polynomials are used to describe the excess Gibbs energy of the liquid. Two sets of self-consistent thermodynamic parameters are obtained by considering reliable experimental data and the computed enthalpies of formation. Comprehensive comparisons between the calculated and measured phase diagram and thermodynamic data show that the experimental information is satisfactorily accounted for by the present thermodynamic description.

Thermodynamic Analysis of Steels by Incorporating First-Principles Calculations into the CALPHAD Approach

2007 ◽  
Vol 539-543 ◽  
pp. 2413-2418 ◽  
Author(s):  
Hiroshi Ohtani ◽  
N. Hanaya ◽  
Mitsuhiro Hasebe
Keyword(s):  
Phase Diagrams ◽  
Thermodynamic Analysis ◽  
First Principles ◽  
Experimental Information ◽  
Full Potential ◽  
Calphad Approach ◽  
First Principles Calculations ◽  
Plane Wave Method ◽  
Ternary Phase Diagrams ◽  
High Degree

A thermodynamic analysis of the Fe−M−P (M = Nb, Ti) ternary system has been performed by combining first-principles calculations with the CALPHAD approach. Because of the lack of experimental information available, thermodynamic properties of orthorhombic anti-PbCl2-type FeMP were evaluated using the Full Potential Linearized Augmented Plane Wave method, and the estimated values were introduced into a CALPHAD-type thermodynamic analysis. Applying this procedure, the phase diagrams of the Fe−M−P ternary phase diagrams whose contents are uncertain so far were calculated with a high degree of probability. Phase diagrams for high-purity ferritic stainless steels obtained following the same procedure are also presented.

scholarly journals Thermodynamic Modeling and Mechanical Properties of Mg-Zn-{Y, Ce} Alloys: Review

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1592
Author(s):  
Mohammad Aljarrah ◽  
Jasim Alnahas ◽  
Mohammed Alhartomi
Keyword(s):  
Mechanical Properties ◽  
Thermodynamic Modeling ◽  
Binary Systems ◽  
Ternary Phase ◽  
Precipitation Hardening ◽  
Calphad Approach ◽  
First Principles Calculations ◽  
Specific Strength ◽  
Ternary Phase Diagrams ◽  
Strong Candidate

Magnesium alloys are a strong candidate for various applications in automobile and aerospace industries due to their low density and specific strength. Micro-alloying magnesium with zinc, yttrium, and cerium enhances mechanical properties of magnesium through grain refinement and precipitation hardening. In this work, a critical review of magnesium-based binary systems including Mg-Zn, Mg-Y, Mg-Ce, Zn-Y, and Zn-Ce is presented. Based on the CALPHAD approach and first-principles calculations, thermodynamic modeling of Mg-Zn-Y and Mg-Zn-Ce ternary phase diagrams have been summarized. The influence of micro-alloying (yttrium and cerium) on the mechanical properties of magnesium is discussed. A comparison between mechanical properties of magnesium commercial alloys and magnesium–zinc–{yttrium and cerium} have been summarized in tables.

scholarly journals An approach to determine enthalpies of formation for ternary compounds

2010 ◽  
Vol 46 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Y. Du ◽  
J. Wang ◽  
Y.F. Ouyang ◽  
L.J. Zhang ◽  
Z.H. Yuan ◽  
...  
Keyword(s):  
Experimental Data ◽  
First Principles ◽  
Integrated Approach ◽  
Enthalpies Of Formation ◽  
Calphad Approach ◽  
Miedema Model ◽  
Theoretical Computation ◽  
Ternary Compounds ◽  
Data Yield ◽  
Experimental Values

An integrated approach of experiment and theoretical computation to acquire enthalpies of formation for ternary compounds is described. The enthalpies of formation (DHf ) for Al71Fe19Si10 and Al31Mn6Ni2 are measured via a calorimeter. Miedema model, CALPHAD and first-principles method are employed to calculate DHf for the above compounds and several Al-based ternary compounds. It is found that first-principles generated data yield good agreements with experimental values and thus can be used as key 'experimental data', which are needed for CALPHAD approach.

Thermodynamic Calculation of Phase Equilibria in the Mn-RE (RE=Nd, Gd, Dy) Binary Systems

2017 ◽  
Vol 898 ◽  
pp. 1036-1041
Author(s):  
M.H. Rong ◽  
S.D. Lin ◽  
Jiang Wang ◽  
H.Y. Zhou ◽  
G.H. Rao
Keyword(s):  
Magnetic Properties ◽  
Thermodynamic Properties ◽  
Phase Equilibria ◽  
Thermodynamic Calculation ◽  
Binary Systems ◽  
Ternary Systems ◽  
Experimental Information ◽  
Calphad Method ◽  
Self Consistent ◽  
Ternary Intermetallic Compounds

Ternary intermetallic compounds with rare earth elements and transition metals in the RE-Mn-X (X=Si, Ge, Sn etc.) ternary systems show interesting magnetic properties. As key sub-binary systems of the RE-Mn-X (X=Si, Ge, Sn etc.) ternary systems, the information of phase equilibria and thermodynamic properties of the Mn-RE (RE=Nd, Gd, Dy) binary systems are indispensable to explore the RE-Mn-X (X=Si, Ge, Sn etc.) alloys with better magnetic properties. In this work, the experimental data of phase equilibria and thermodynamic properties of the Mn-RE (RE=Nd, Gd, Dy) binary systems in the published literature were reviewed. Based on the available experimental information, thermodynamic calculation of phase equilibria of the Mn-RE (RE=Nd, Gd, Dy) binary systems was performed using the CALPHAD method. As a result, further experimental investigation and thermodynamic optimization would be still necessary in order to develop the self-consistent and compatible thermodynamic database of the RE-Mn-based alloy systems.

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