scholarly journals Thermodynamic predicting of Si-Me (Me = Ti, Al) binary systems

2007 ◽  
Vol 43 (1) ◽  
pp. 29-38 ◽  
Author(s):  
A. Kostov ◽  
D. Zivkovic ◽  
B. Friedrich
Keyword(s):  
Phase Diagrams ◽  
Thermodynamic Analysis ◽  
Binary Systems ◽  
Thermodynamic Calculations ◽  
Gibbs Energies ◽  
Different Temperatures ◽  
Thermodynamic Determination

Thermodynamic predicting analysis of Si-based binary systems - Ti-Si, and Al-Si, are shown in this paper. Thermodynamic analysis involved thermodynamic determination of activities, coefficient of activities, partial and integral values for enthalpies and Gibbs energies of mixing and excess energies at different temperatures: 2000K, 2400K and 2473K, as well as calculation of phase diagrams for the investigated binaries. The FactSage was used for all thermodynamic calculations. .

scholarly journals Thermodynamic study of Ti-V and Al-V systems using FactSage

2006 ◽  
Vol 42 (1) ◽  
pp. 57-65 ◽  
Author(s):  
A. Kostov ◽  
D. Zivkovic ◽  
B. Friedrich
Keyword(s):  
Phase Diagrams ◽  
Binary Systems ◽  
Thermodynamic Study ◽  
Thermodynamic Calculations ◽  
Calculated Phase ◽  
Gibbs Energies ◽  
Different Temperatures ◽  
Thermodynamic Determination

Thermodynamic study of Ti-V and Al-V binary systems is presented in this paper. Investigations included thermodynamic determination of activities, coefficient of activities, partial and integral values Gibbs energies of mixing and excess energies at four different temperatures: 2000K, 2073K, 2200K and 2273K, as well as calculated phase diagrams for the investigated systems. The FactSage program was used for all thermodynamic calculations.

scholarly journals Thermodynamic calculations in alloys Ti-Al, Ti-Fe, Al-Fe and Ti-Al-Fe

2008 ◽  
Vol 44 (1) ◽  
pp. 49-61 ◽  
Author(s):  
Ana Kostov ◽  
B. Friedrich ◽  
D. Zivkovic
Keyword(s):  
Phase Diagrams ◽  
Ternary Alloy ◽  
Ternary Systems ◽  
Thermodynamic Calculations ◽  
Calculated Phase ◽  
Gibbs Energies ◽  
Different Temperatures ◽  
Binary And Ternary Systems ◽  
Thermodynamic Determination

Thermodynamic calculations of three binary Ti-based alloys: Ti-Al, Ti-Fe, and Al-Fe, as well as ternary alloy Ti-Al-Fe, is shown in this paper. Thermodynamic calculations involved thermodynamic determination of activities, coefficient of activities, partial and integral values for enthalpies and Gibbs energies of mixing and excess energies at different temperatures: 1873K, 2000K and 2073K, as well as calculated phase diagrams for the investigated binary and ternary systems. The FactSage is used for all thermodynamic calculations.

scholarly journals Thermodynamic calculations in ternary titanium-aluminium-manganese system

2008 ◽  
Vol 73 (4) ◽  
pp. 499-506 ◽  
Author(s):  
Ana Kostov ◽  
Dragana Zivkovic
Keyword(s):  
Experimental Data ◽  
Thermodynamic Properties ◽  
Ternary System ◽  
Thermodynamic Analysis ◽  
Experimental Results ◽  
Thermodynamic Calculations ◽  
Thermodynamic Optimization ◽  
Gibbs Energies ◽  
Different Temperatures ◽  
Titanium Aluminium

Thermodynamic calculations in the ternary Ti-Al-Mn system are shown in this paper. The thermodynamic calculations were performed using the FactSage thermochemical software and database, with the aim of determining thermodynamic properties, such as activities, coefficient of activities, partial and integral values of the enthalpies and Gibbs energies of mixing and excess energies at two different temperatures: 2000 and 2100 K. Bearing in mind that no experimental data for the Ti-Al-Mn ternary system have been obtained or reported. The obtained results represent a good base for further thermodynamic analysis and may be useful as a comparison with some future critical experimental results and thermodynamic optimization of this system.

Electrochemical Determination of Phase Diagrams and Thermodynamic Data of Multi-Component Systems

1980 ◽  
Vol 35 (4) ◽  
pp. 381-388 ◽  
Author(s):  
W. Weppner ◽  
Chen Li-chuan ◽  
W. Piekarczyk
Keyword(s):  
Phase Diagrams ◽  
Coulometric Titration ◽  
Equilibrium Phase ◽  
Cell Voltage ◽  
Electrochemical Determination ◽  
Specific Cell ◽  
Gibbs Energies ◽  
Component Systems ◽  
Titration Technique

Abstract The coulometric titration technique is extended to treat general cases of systems of any number of components. Complete equilibrium phase diagrams and thermodynamic properties are obtained from readily and precisely measurable electrical quantities, employing only a small number of samples. General equations are derived which directly relate the cell voltage to the standard Gibbs energies, enthalpies and entropies of formation of all phases involved without the necessity of considering specific cell reactions. The application of the technique to the ternary system Cu-Ge-O is demonstrated.

scholarly journals THERMODYNAMIC MODELING OF OXIDE MELTS OF CaO - Al2O3 - SiO2 SYSTEMS

2019 ◽  
Vol 63 (1) ◽  
pp. 45-50
Author(s):  
Svetlana E. Pratskova ◽  
Vladimir A. Burmistrov ◽  
Anna A. Starikova
Keyword(s):  
Phase Diagrams ◽  
Thermodynamic Modeling ◽  
Binary Systems ◽  
Thermodynamic Description ◽  
Ternary Systems ◽  
Oxide Melt ◽  
State Diagrams ◽  
Gibbs Energies ◽  
Metallurgical Slags ◽  
Oxide Melts

Oxide melts of the CaO – Al2O3 – SiO2 system are the basis of metallurgical slags. Therefore, the thermodynamic properties of this system have been repeatedly studied experimentally, and attempts have been made to describe them theoretically. Thermodynamic modeling of the state diagrams of the CaO – Al2O3, CaO – SiO2, Al2O3 – SiO2 binary systems, as well as the CaO – Al2O3 – SiO2 ternary system was performed. In the course of the work, expressions for the thermodynamic description of the activities of the components of the oxide melt of this system are derived. For the calculation, a generalized theory of regular ionic solutions was used. The energy parameters of the theory are determined, depending on the temperature and composition of the solution, using experimental data on the heat and melting point of oxides of calcium, aluminum and silicon. According to the results of the simulation, the coordinates of the points of nonvariant transformations in the phase diagrams of the binary and ternary systems under study are determined. The obtained results on thermodynamic modeling of the coordinates of the liquidus lines of the phase diagrams of the CaO – Al2O3, CaO – SiO2, Al2O3 – SiO2 binary systems were compared with the literature data for the studied systems. The calculated diagrams are in good agreement with the experimental ones, which indicates the applicability of the chosen system for the description of such oxide melts. The modeling technique used in this work allowed to estimate the Gibbs energies of formation of silicates and calcium aluminum silicates to be 3Al2O3∙2SiO2, 3CaO∙SiO2, 2CaO∙SiO2, 3CaO∙2SiO2, CaO∙SiO2, CaO∙Al2O3∙2SiO2, 2CaO∙Al2O3∙SiO2 on the base of obtained aquations for of activities of the components and calculated parameters of the theory. The calculated diagrams will allow to determine the nature of the interaction between the components of the system, the conditions of formation, the composition and properties of the compounds formed, without isolating them from the system.

scholarly journals Thermodynamic Stability of Fenclorim and Clopyralid

2021 ◽  
Author(s):  
Ana R.R.P. Almeida ◽  
Bruno D.A. Pinheiro ◽  
Ana I.M.C. Lobo Ferreira ◽  
Manuel J.S. Monte
Keyword(s):  
Thermodynamic Stability ◽  
Accurate Determination ◽  
Supercooled Liquid ◽  
Drop Calorimetry ◽  
Vapor Pressures ◽  
Scanning Calorimetry ◽  
Gibbs Energies ◽  
Liquid Phases ◽  
Different Temperatures

The present work reports an experimental thermodynamic study of two nitrogen heterocyclic organic compounds, fenclorim and clopyralid, that have been used as herbicides. The sublimation vapor pressures of fenclorim (4,6-dichloro-2-phenylpyrimidine) and of clopyralid (3,6-dichloro-2-pyridinecarboxylic acid) were measured, at different temperatures, using a Knudsen mass-loss effusion technique. The vapor pressures of both crystalline and liquid (including supercooled liquid) phases of fenclorim were also determined using a static method based on capacitance diaphragm manometers. The experimental results enabled accurate determination of the standard molar enthalpies, entropies and Gibbs energies of sublimation for both compounds and of vaporization for fenclorim, allowing a phase diagram representation of the (p,T) results, in the neighborhood of the triple point of this compound. The temperatures and molar enthalpies of fusion of the two compounds studied were determined using differential scanning calorimetry. The standard isobaric molar heat capacities of the two crystalline compounds were determined at 298.15 K, using drop calorimetry. The gas phase thermodynamic properties of the two compounds were estimated through ab initio calculations, at the G3(MP2)//B3LYP level, and their thermodynamic stability was evaluated in the gaseous and crystalline phases, considering the calculated values of the standard Gibbs energies of formation, at 298.15 K.

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