| 1. |
- Andersson, J. O., et al.
(författare)
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THERMO-CALC & DICTRA, computational tools for materials science
- 2002
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Ingår i: Calphad. - 0364-5916 .- 1873-2984. ; 26:2, s. 273-312
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Tidskriftsartikel (refereegranskat)abstract
- Software for calculation of phase diagrams and thermodynamic properties have been developed since the 1970's. Software and computers have now developed to a level where such calculations can be used as tools for material and process development. In the present paper some of the latest software developments at Thermo-Calc Software are presented together with application examples. It is shown how advanced thermodynamic calculations have become more accessible since: - A more user-friendly windows version of Thermo-Calc, TCW, has been developed. - There is an increasing amount of thermodynamic databases for different materials available. - Thermo-Calc can be accessed from user-written software through several different programming interfaces are available which enables access to the thermodynamic software from a user-written software. Accurate data for thermodynamic properties and phase equilibria can then easily be incorporated into software written in e.g. C++, Matlab and FORTRAN. Thermo-Calc Software also produces DICTRA, a software for simulation of diffusion controlled phase transformations. Using DICTRA it is possible to simulate processes such as homogenization, carburising, microsegregation and coarsening in multicomponent alloys. The different models in the DICTRA software are briefly presented in the present paper together with some application examples.
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| 2. |
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| 3. |
- Bjorkvall, J., et al.
(författare)
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Thermodynamic description of Al2O3-CaO-MnO and Al2O3-FeO-MnO melts - a model approach
- 2000
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Ingår i: Calphad. - 0364-5916 .- 1873-2984. ; 24:3, s. 353-376
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Tidskriftsartikel (refereegranskat)abstract
- Assessments for the binary systems. Al2O3-CaO, Al2O3-FeO and Al2O3-MnO were carried out using a slag model developed at the present department. Calculations of the oxide activities in the homogenous liquid phase have been performed for the Al2O3-CaO-MnO and Al2O3-FeO-MnO systems, The activities in the ternary systems were calculated using the parameters obtained from the binary subsystems. Comparison between experimental data and the model calculations demonstrates the ability of the model to describe the thermodynamics of ternary systems using only information ti-om the binary systems. In the case of the Al2O3-CaO-MnO system, the comparison between model calculations and the results of the only available experimental measurements is less satisfactory. This could partly be attributed to the non availability of experimental data for the subsystem CaO-MnO. Future experimentation in the Al2O3-CaO-MnO system is strongly recommended.
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| 4. |
- Bratberg, Johan, et al.
(författare)
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A thermodynamic analysis of the Mo-V and Mo-V-C systems
- 2002
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Ingår i: Calphad. - 0364-5916 .- 1873-2984. ; 26:3, s. 459-503
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Tidskriftsartikel (refereegranskat)abstract
- A new thermodynamic evaluation of the binary Mo-V system and the ternary Mo-V-C system using thermodynamic models for the Gibbs energy of individual phases is presented. The CALPHAD method has been used, with predictions of unknown thermodynamic quantities, to optimize a set of thermodynamic parameters taking related experimental information into consideration. The predictions are based on regularities in bonding properties and vibrational entropy of 3d-transition metal carbides. The results are summarized in tables of thermodynamic parameters, calculated binary phase diagrams and isothermal sections of the ternary phase diagram compared with experimental information. Finally the influence of ternary interaction parameters, especially in the fcc phase, on calculations of equilibria in multicomponent systems is discussed.
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| 5. |
- Dupin, N., et al.
(författare)
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Thermodynamic re-assessment of the ternary system Al-Cr-Ni
- 2001
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Ingår i: Calphad. - 0364-5916 .- 1873-2984. ; 25:2, s. 279-298
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Tidskriftsartikel (refereegranskat)abstract
- A re-assessment of the ternary system AI-Cr-Ni following Dupin's thesis work using a single Gibbs energy function for the gamma and gamma' phases is presented taking into account new experimental liquidus temperatures. The disordered bcc A2 and ordered B2 phases are also modelled with a single equation. The existence of vacancies as defects in this structure is described. The other phases are modelled as substitutional solutions, or as stoichiometric or non-stroichiometric binary compounds. The present assessment is limited to the sub system AlNi-Cr-Ni where no ternary phase exists. The parameters describing the Gibbs energy of all the assessed phases are given. Extensive comparisons between calculation and experimental data are presented.
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| 6. |
- Fredriksson, P., et al.
(författare)
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A thermodynamic assessment of the Fe-Pt system
- 2001
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Ingår i: Calphad. - 0364-5916 .- 1873-2984. ; 25:4, s. 535-548
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Tidskriftsartikel (refereegranskat)abstract
- The present work will present a complete assessment of the Fe-Pt system by means of the CALPHAD method. The liquid and the bee phase have been modelled as substitutional solutions where the interaction parameter is composition dependent in the form of a Redlich-Kister series. The ordered phases and the disordered fee phases were modelled in CEF formalism with a single Gibbs energy function. The obtained phase equilibria and activities of iron and platinum agree reasonably well with the literature data. Validation of the liquidus maxima around 50 at% Pt, found in the optimisation work, was performed by a quenching experiment followed by SEM analysis.
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| 7. |
- Hillert, M., et al.
(författare)
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Predicting miscibility gaps in reciprocal liquids
- 2001
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Ingår i: Calphad. - 0364-5916 .- 1873-2984. ; 25:4, s. 599-605
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Tidskriftsartikel (refereegranskat)abstract
- There is a strong correlation between the appearance of liquid miscibility gaps in reciprocal phases and the standard Gibbs energy of the reciprocal reaction, DeltadegreesG. The associate solution model does not predict such a correlation but the two-sublattice model does. Physically, the critical temperature of a reciprocal miscibility gap is related to DeltadegreesG and is also affected by the presence of short range order. The latter effect can be estimated from DeltadegreesG using the conformal solution theory which was developed for reciprocal systems with univalent ions. In that approximation the short range order effect is described with a reciprocal parameter. The estimate of that parameter for systems with different valencies is now discussed. The calculated phase diagram may be reasonable for low values of the reciprocal parameter, relative to DeltadegreesG, but is not satisfactory for large values because two asymmetric miscibility gaps will appear when the critical temperature has been suppressed to 3/4 of the value predicted without a reciprocal term. An alternative form of the reciprocal term is now proposed, which does not produce the splitting into two miscibility gaps.
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| 8. |
- Jerlerud Perez, Rosa, et al.
(författare)
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Thermodynamic assessment of the CR-SN binary system
- 2001
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Ingår i: Calphad. - 0364-5916 .- 1873-2984. ; 25:1, s. 59-66
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Tidskriftsartikel (refereegranskat)abstract
- A thermodynamic description of the Cr-Sn binary system has been obtained using the CALPHAD technique. The excess Gibbs energy of the stable solution phases (liquid and bcc) has been assessed using phase diagram and thermodynamic data.
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| 9. |
- Kusoffsky, A., et al.
(författare)
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On the compound energy formalism applied to fcc ordering
- 2001
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Ingår i: Calphad. - 0364-5916 .- 1873-2984. ; 25:4, s. 549-565
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Tidskriftsartikel (refereegranskat)abstract
- The influence on the phase diagram and thermodynamic properties of some parameters in the Compound Energy Formalism (CEF) is studied for different simple binary and ternary cases showing fcc ordering. It is shown that the flexibility of this formalism should enable to model most real cases. Recommendations for the ternary parameters that should be set from the binary systems are made.
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| 10. |
- Pei, Benyan, et al.
(författare)
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A thermodynamic assessment of the iron - Antimony system
- 1995
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Ingår i: Calphad. - 0364-5916 .- 1873-2984. ; 19:1, s. 1-15
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Tidskriftsartikel (refereegranskat)abstract
- A critical assessment of the Fe-Sb system was carried out by using a computerized technique. Both the liquid and solid solution phases were described by regular solution models. Nonstoichiometric phase, ε-FeSb, was modeled as (Fe)(Fe,Sb), and FeSb2 was treated as a stoichiometric compound. A set of parameters describing the Gibbs energies of the different phases was optimized by using the existing phase diagram information and thermodynamic properties under one atmosphere. Assessed phase diagram and thermodynamic data are presented and compared with experimental data.
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