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The thermodynamic properties including enthalpy, entropy and Gibbs free energy of 15 types of pure polymers were derived from experimental data of heat capacity, as a function of temperature. The calculated results are presented in both polynomial expressions and graphs. This database of pure polymers will provide basic parameters in assessments of phase diagrams in binary, ternary and higher-order...
The thermodynamic modelling of the binary C–Pu system was performed in the framework of the development of a thermodynamic database for nuclear materials, for increasing the knowledge of the physico-chemical behaviour of the fuel and surrounding materials implicated in GFR (gas cooled fast reactor) systems. The critical assessment was carried out using the CALPHAD approach, based on available experimental...
Amorphous alloys are metastable phases which have generated considerable interest in recent years because of their promising properties. This review considers thermodynamic and kinetic aspects in the modelling of metallic amorphous phases.The relevant literature on the glass transition and the thermodynamics of amorphous phases is discussed in detail. The CALPHAD approach is used for thermodynamic...
As part of the construction of a Cu–In–Ga–Se quaternary thermodynamic database, which is essential to the optimization of a high-efficiency Cu(In,Ga)Se 2 -based thin film solar cell process, a complete thermodynamic description for the Ga–Se binary system was established by thermodynamic optimization. The calculated thermodynamic properties and phase diagrams agree well with the experimental...
A preliminary thermodynamic assessment of the Ir–Nb system, one of the key binary systems of the Ir-based refractory superalloys, has been performed by combining ab initio calculations and the CALPHAD (CALculation of PHAse Diagrams) technique. The ground-state formation enthalpies have been calculated by the full-potential linearized augmented plane wave method. The free energies at finite temperatures...
The V–Si system is reassessed based on a critical literature review involving recently reported data and the present experimental data. These new data include the thermodynamic stability of V 6 Si 5 and the enthalpies of formation for the compounds calculated by first-principles method. Two alloys were prepared in the region of (Si)+V Si 2 and annealed at 1273 K for 14 days...
A thermodynamic description is presented for ternary Cu–Mg–Ni and Cu–Mg–Zn systems. Thermodynamic parameters of binary sub-systems, Cu–Mg, Cu–Ni, Cu–Zn, Mg–Ni and Mg–Zn, are taken from earlier SGTE-based assessments and those of the Cu–Mg–Ni and Cu–Mg–Zn systems are optimized in this study using experimental phase equilibrium and thermodynamic data. Solution phases of the systems are described with...
The temperature of the degenerated invariant reaction in the Cu–V system was accurately determined by means of Differential Scanning Calorimetry (DSC) measurements. On the basis of the experimental data from the present work and those critically assessed from the literature, an optimal thermodynamic data set for the Cu–V system was obtained. Significant improvements have been made, compared with the...
As part of an extensive study devoted to the development of new high-Al steels, a CALPHAD-type assessment of the Al–Fe–C system has been carried out. In place of the usual cementite, these steels show precipitation of the so-called κ carbide that is an ordered form of austenite. Inconsistencies between the scarce experimental information in the Al–Fe–C system and extrapolations from the available...
Phase equilibria and thermodynamic properties at 1 bar in the Y 2 O 3 –Al 2 O 3 –SiO 2 ternary system and its constituent binaries Y 2 O 3 –Al 2 O 3 and Y 2 O 3 –SiO 2 have been reevaluated using the CALPHAD approach. The liquid phase is described by the ionic two-sublattice model with the formula (Al ...
Published experimental thermodynamic and phase diagram data for the Ca–Zn, Sr–Zn, Y–Zn and Ce–Zn systems have been critically evaluated to provide assessed thermodynamic parameters for the different phases of the systems. The parameters allow all thermodynamic properties and phase boundaries for each system to be calculated within reasonable error limits. Because a strong compound-forming tendency...
The phase equilibria and thermodynamic properties of the Cu–Pd system are optimized using the CALPHAD (CALculation of PHAse Diagram) technique. In the present work, the liquid and face-centered cubic (fcc) solution phases are modeled with the substitutional solution model. A two-sublattice model (Cu,Pd) 0.75 (Cu,Pd) 0.25 is applied to describe the ordered Cu 3 Pd phase, the...
Experimental studies of carburisation of diffusion couples Fe/Fe–4 at.% Si, Fe/Fe–7.5 at.% Mo and Fe/Fe–20 at.% V are reported. The diffusion couples were carburised at 700 ∘ C for 10 h in a strongly carburising CO–H 2 –H 2 O–H 2 S gas mixture imposing a carbon activity aC=100. The growth of cementite at the surface of the couples was found to depend on the concentration...
New critical evaluations and optimizations of the Al–Ce, Al–Y, Al–Sc and Mg–Sc systems are presented. The Modified Quasichemical Model is used for the liquid phases which exhibit a high degree of short-range ordering. A number of solid solutions in the binary systems are modelled using the Compound Energy Formalism. All available and reliable experimental data such as enthalpies of mixing in liquid...
A thermodynamic assessment of the Cu–Ga system was carried out by the CALPHAD approach (CALculation of PHase Diagram). The liquid phase, the solid solution phases of fcc (α-Cu), bcc (β) and hcp (ζ), the solution compounds of Cu 9 Ga 4_ 0 (γ0), Cu 9 Ga 4_ 1 (γ1), Cu 9 Ga 4_ 2 (γ2) and Cu 9 Ga 4_ 3 (γ3), the stoichiometric compounds of...
The ternary system Bi–Fe–Sb has been investigated using differential thermal analysis (DTA), differential scanning calorimetry (DSC) and electron probe microanalysis (EPMA). Two isoplethic sections were studied: 80 at.% Bi and 30 at.% Sb. An isothermal section of the phase diagram was also studied at 523.15 K. Three invariant reactions were found: two ternary transitory peritectics and one ternary...
Thermodynamic descriptions of multicomponent carbides and carbonitrides with Nb, Ti and V, evaluated using experimental information from the literature, are presented. The descriptions are validated by calculating solubilities of the carbides and carbonitrides in cemented carbides and steel, and comparing them with experimental information. The agreement is good, and it is shown that the agreement...
Phase equilibria calculations require the knowledge of the whole Gibbs energy functions referred to standard elements. Nevertheless, in mechanical calculations the relative change in free energy, already formulated by Landau is often used for the description of the elastic energy of a solid. In order to have a better consistency between the two approaches, it is now suggested a formulation of the...
The thermodynamic expressions for the phases found in the aluminum-rich corner of the Al–Cu–Mg–(Ag) system were evaluated and refined to develop a self-consistent database. Microstructural characterization and thermal analysis aided in revising published thermodynamic data for the Al–Cu–Mg and Al–Cu–Mg–Ag systems. To represent the presence of silver an additional interaction energy term was formulated...
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