Change search
Refine search result
12 1 - 50 of 98
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Allertz, Carl
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Sichen, Du
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    The Effect of Oxygen Potential on the Sulfide Capacity for Slags Containing Multivalent Species2016In: Metallurgical and materials transactions. B, process metallurgy and materials processing science, ISSN 1073-5615, E-ISSN 1543-1916, Vol. 47, no 5, p. 3039-3045Article in journal (Refereed)
    Abstract [en]

    The dependence of sulfide capacity on the oxygen partial pressure for slags containing multivalent species was investigated experimentally using a slag containing vanadium oxide. Copper-slag equilibration experiments were carried out at 1873 K (1600 A degrees C) in the approximate oxygen partial pressure range 10(-15.4) to 10(-9) atm. The sulfide capacity was found to be strongly dependent on the oxygen potential in this slag system, increasing with the oxygen partial pressure. The sulfide capacity changed by more than two orders of magnitude over the oxygen partial pressure range. The effect of changing oxygen partial pressure was found to be much greater than the effect of changing slag composition at a fixed oxygen partial pressure.

  • 2.
    Arvhult, Carl
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Gueneau, Christine
    Univ Paris Saclay, CEA, DEN, SCCME, F-91191 Gif Sur Yvette, France..
    Gosse, Stephane
    Univ Paris Saclay, CEA, DEN, SCCME, F-91191 Gif Sur Yvette, France..
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Thermodynamic assessment of the Ni-Te system2019In: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 54, no 16, p. 11304-11319Article in journal (Refereed)
    Abstract [en]

    A thermodynamic assessment of the Ni-Te system has been performed using the Calphad method, based on experimental data available in the literature. The proposed description has been developed for use in the modeling of fission-product-induced internal corrosion of stainless steel cladding in Generation IV nuclear reactors. DFT calculations were performed to obtain 0 K properties of solid phases to assist the thermodynamic optimization. The ionic liquid two-sublattice model was used, and most solution phases were modeled using interstitial metal sub-lattices. With a strict number of parameters, the resulting description satisfactorily reproduces all thermodynamic properties and high-temperature phase transitions. The metastable miscibility gap in the Ni-rich liquid that is experimentally suggested is not present in the final description. The phase exhibits a metastable order-disorder transition between the CdI2 and NiAs types of interstitial nickel distribution. The CdI2 prototype is the stable space group at room temperature. Low-temperature ordering phase transitions have been disregarded in this description, since they are not of interest to the application of corrosion in nuclear reactors.

  • 3.
    Arvhult, Carl-M
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Physical Metallurgy.
    Gueneau, C.
    Univ Paris Saclay, DEN, SCCME, CEA, F-91191 Gif Sur Yvette, France..
    Gosse, S.
    Univ Paris Saclay, DEN, SCCME, CEA, F-91191 Gif Sur Yvette, France..
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Thermodynamic assessment of the Fe-Te system. Part II: Thermodynamic modeling2018In: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 767, p. 883-893Article in journal (Refereed)
    Abstract [en]

    A thermodynamic description of the Fe-Te system modeled via the Calphad method is proposed, based on data published in a preceding publication Part I: Experimental study, and that available in literature. End-member formation energies for the phases beta, beta', delta, delta' and epsilon, as well as lattice stabilities of FCC and BCC tellurium, have been evaluated via DFT and used in the numerical optimization. The final Gibbs energy models fit thermodynamic and phase diagram data well, and inconsistencies are discussed. The thermodynamic description is then used to evaluate Gibbs energy of formation for selected Fe-Te compounds of interest for the modeling of internal corrosion of stainless steel fuel pin cladding during operation of Liquid Metal-cooled Fast Reactors (LMFR).

  • 4. Becker, Chandler A.
    et al.
    Ågren, John
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Physical Metallurgy.
    Baricco, Marcello
    Chen, Qing
    Decterov, Sergei A.
    Kattner, Ursula R.
    Perepezko, John H.
    Pottlacher, Gernot R.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Thermodynamic modelling of liquids: CALPHAD approaches and contributions from statistical physics2014In: Physica status solidi. B, Basic research, ISSN 0370-1972, E-ISSN 1521-3951, Vol. 251, no 1, p. 33-52Article in journal (Refereed)
    Abstract [en]

    We describe current approaches to thermodynamic modelling of liquids for the CALPHAD method, the use of available experimental methods and results in this type of modelling, and considerations in the use of atomic-scale simulation methods to inform a CALPHAD approach. We begin with an overview of the formalism currently used in CALPHAD to describe the temperature dependence of the liquid Gibbs free energy and outline opportunities for improvement by reviewing the current physical understanding of the liquid. Brief descriptions of experimental methods for extracting high-temperature data on liquids and the preparation of undercooled liquid samples are presented. Properties of a well-determined substance, B-2 O-3, including the glass transition, are then discussed in detail to emphasize specific modelling requirements for the liquid. We then examine the two-state model proposed for CALPHAD in detail and compare results with experiment and theory, where available. We further examine the contributions of atomic-scale methods to the understanding of liquids and their potential for supplementing available data. We discuss molecular dynamics (MD) and Monte Carlo methods that employ atomic interactions from classical interatomic potentials, as well as contributions from ab initio MD. We conclude with a summary of our findings.

  • 5.
    Bigdeli, Sedigheh
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Ehtehsami, Hossein
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Chen, Qing
    Mao, Huahai
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Korzhavyi, Pavel A.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    New description of metastable hcp phase for unaries Fe and Mn: Coupling between first-principles calculations and CALPHAD modeling2016In: Physica Status Solidi B, ISSN 1521-3951, no 9, p. 1830-1836Article in journal (Refereed)
    Abstract [en]

    The main focus in developing the third generation of CALPHADdatabases is to model thermodynamic properties of materialsby using models which are more physically based andvalid down to 0K. First-principles calculations are helpful tochoose and validate those models. Reliable calculation results,for example, at very low temperatures or on metastable systemsreveal physical facts which might be inaccessible by experiments.Following our earlierwork for modeling thermodynamicproperties of pure elements (i.e., Fe and Mn) in third-generationCALPHAD databases, the (hcp) phase was modeled as ametastable phase in the present work. Although hcp phase isjust observed in these two elements under ultra-high pressure, inthe binary Fe–Mn this phase is metastable at ambient temperaturesand pressures. Therefore, it should be properly modeled inunaries for later optimization of binary systems. Based on densityfunctional theory (DFT) calculations, the magnetic groundstate and the magnetic properties of -Fe, -Mn, and their binarysolution phase were calculated. It was found that -Fe is antiferromagnetic(type II) while -Mn has a paramagnetic groundstate. Accordingly, magnetic contributions to thermodynamicproperties were accurately modeled. Moreover, by means ofthe extrapolation of experimental data for the thermodynamicproperties of binary systems and high-pressure data for unaries,the metastable hcp phases at ambient pressure were modeledfor the third-generation CALPHAD database, consistently withother stable phases in the elements Fe and Mn.

  • 6.
    Bigdeli, Sedigheh
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Mao, Huahai
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    On the third-generation Calphad databases: An updated description of Mn2015In: Physica status solidi. B, Basic research, ISSN 0370-1972, E-ISSN 1521-3951, Vol. 252, no 10, p. 2199-2208Article in journal (Refereed)
    Abstract [en]

    Aiming for better extrapolations and predictabilities of thermodynamic properties of materials, new thermodynamic models are implemented in the third-generation Calphad databases. In these models, each term contributing to the Gibbs energy has an explicit physical meaning. Furthermore, descriptions of thermodynamic properties of materials are valid from 0K up to high temperatures far above the melting point. As a starting point for the development of large self-consistent third-generation database, the new models in the present work are applied to the unary manganese system. Taking into account both the calculated first principles results and experimental data, thermodynamic model parameters are evaluated. Thermodynamic properties predicted using this description, agree very well with available data. The calculated properties vary smoothly in the whole temperature range, which is another important improvement compared to the second-generation databases.

  • 7.
    Bigdeli, Sedigheh
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Qing, Chen
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    A new description for pure C; in developing the third generation of Calphad databases.In: Journal of Phase Equilibria and DiffusionArticle in journal (Other academic)
    Abstract [en]

    In connection to developing the third generation of Calphad databases a new thermodynamic description is presented for unary carbon. Models used in this work have more physical basis and are valid down to 0 K. The anisotropy in graphite, caused by weak Van der Waals inter-plane forces makes it difficult to fit the heat capacity data by a single Einstein tempera-ture for modelling the harmonic vibration of the atoms. By using multiple Einstein temperatures this problem is solved and a good agreement with the experimental data at low temperatures is achieved. Diamond is mod-eled using new models too, and the two-state model is used for modelling the liquid phase.

  • 8.
    Bigdeli, Sedigheh
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics. KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Physical Metallurgy.
    A thermodynamic assessment of the binary Fe-Mn system for the third generation of Calphad databases2017Manuscript (preprint) (Other academic)
    Abstract [en]

    In developing the third generation of Calphad databases, after having proper models for the unaries, the next step is to assess higher-order systems, i.e. binaries, ternaries etc. A new description for the Fe-Mn system is presented in this work, based on the Calphad approach. New models with a stronger physical basis are used to model Gibbs energy of the phases. For this purpose, the revised magnetic model is used to fit the magnetic properties versus the most recent experimental and DFT data. An acceptable magnetic phase diagram is reproduced, which results in a more reasonable fit for the phase diagram and will prevent possible artefacts in higher-order systems. The descriptions are valid down to 0 K, which make them very useful as an input for modelling phase transformations occurring at low temperatures.  

  • 9.
    Bigdeli, Sedigheh
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    A thermodynamic assessment of the binary Fe-Mn system for the third generation of Calphad databases2019In: Calphad, ISSN 0364-5916, E-ISSN 1873-2984, Vol. 64, p. 185-195Article in journal (Refereed)
    Abstract [en]

    In developing the third generation of Calphad databases, the next step after proper description of the unaries is to assess higher-order systems, i.e. binaries, ternaries etc. A new description of the Fe-Mn system is presented in this work, based on the Calphad approach. New models with a stronger physical basis are used to model the Gibbs energy of the phases. For this purpose, the revised magnetic model is used to fit the magnetic properties versus the most recent experimental and ab-initio data. An acceptable magnetic phase diagram is reproduced, and a reasonable fit for the phase diagram is achieved which will prevent possible artefacts in higher-order systems. The description is valid down to 0 K, which make it very useful as a starting point for modelling phase transformations occurring at low temperatures.

  • 10.
    Bigdeli, Sedigheh
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Zhu, L. -F
    Glensk, A.
    Grabowski, B.
    Lindahl, B.
    Hickel, T.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    An insight into using DFT data for Calphad modeling of solid phases in the third generation of Calphad databases, a case study for Al2019In: Calphad, ISSN 0364-5916, E-ISSN 1873-2984, Vol. 65, p. 79-85Article in journal (Refereed)
    Abstract [en]

    In developing the next generation of Calphad databases, new models are used in which each term contributing to the Gibbs energy has a physical meaning. To continue the development, finite temperature density-functional-theory (DFT) results are used in the present work to discuss and suggest the most applicable and physically based model for Calphad assessments of solid phases above the melting point (the breakpoint for modeling the solid phase in previous assessments). These results are applied to investigate the properties of a solid in the superheated temperature region and to replace the melting temperature as the breakpoint with a more physically based temperature, i.e., where the superheated solid collapses into the liquid. The advantages and limitations of such an approach are presented in terms of a new assessment for unary aluminum.

  • 11.
    Bigdeli, Sedigheh
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Zhu, Li-Fang
    Glensk, Albert
    Grabowski, Blazej
    Lindahl, Bonnie
    Hickel, Tilmann
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    An insight into using DFT data for Calphad modelling of solid phases in the third generation of Calphad databases, case study for Al2017Manuscript (preprint) (Other academic)
    Abstract [en]

     In developing the next generation of Calphad databases, new models are used in which each term contributing to the Gibbs energy has a physical meaning. Harmonic vibrations of atoms are modelled using the Einstein temperature; anharmonic vibrations, electronic and magnetic contributions to the solid phases are represented by specific terms. The two-state model is used for the liquid phase. To continue the development, a new description for unary aluminum is presented in this work. In particular, finite temperature density-functional-theory (DFT) results are used to discuss and suggest the most applicable and physically based model for Calphad assessments of solid phases above the melting point. 

  • 12. Borggren, U.
    et al.
    Selleby, Malin
    KTH, Superseded Departments, Materials Science and Engineering.
    A thermodynamic database for special brass2003In: Journal of phase equilibria (Print), ISSN 1054-9714, E-ISSN 1544-1032, Vol. 24, no 2, p. 110-121Article in journal (Refereed)
    Abstract [en]

    In the present work a thermodynamic database for brass alloys is developed. The database may be used to calculate phase diagrams and property diagrams and to simulate solidification, calculations that may be used to develop new alloys and to increase the understanding of existing ones. When developed, such a database reduces the need for further experimental investigations considerably. The present work is focused on so-called special brass (i.e., alloys of Cu and Zn with small additions of, for instance, Al, As, B, Fe, Pb, and/or Si). The database was created using available thermodynamic descriptions and unavailable systems were assessed using the CALPHAD technique. Experimental information was taken from literature and from experimental results obtained in the present work. The database contains the elements Al, Cu, Pb, Si, and Zn. Calculated phase diagrams show that the peritectic reaction in the Cu-Zn system is very sensitive to small additions of Al and Si, which moves the peritectic reaction towards lower Zn contents and higher temperatures.

  • 13.
    Brusewitz Lindahl, Bonnie
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Burton, Benjamin P.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Ordering in ternary BCCalloys applied to the Al-Fe-Mn systemManuscript (preprint) (Other academic)
  • 14.
    Brusewitz Lindahl, Bonnie
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Kangouei, Navid
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    A thermodynamic investigationof the Al-C-Fe-Mn systemManuscript (preprint) (Other academic)
  • 15.
    Brusewitz Lindahl, Bonnie
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Liu, Xuan L.
    Liu, Zi-Kui
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    A thermodynamic re-assessment of Al-V toward an assessment of the ternary Al-Ti-V system2015In: Calphad, ISSN 0364-5916, E-ISSN 1873-2984, Vol. 51, p. 75-88Article in journal (Refereed)
    Abstract [en]

    Titanium alloys are highly sought after due to their excellent mechanical properties. One of the most commonly used Ti alloys is Ti-6Al-4V, which contains 6% Al and 4% V by weight. Despite the popularity of this alloy, no thermodynamic description of the ternary Al-Ti-V system has been published in the open literature. In this work an assessment procedure of the ternary Al-Ti-V system was initiated based on the binary descriptions by Witusiewitcz et al. (J. Alloys Compds. 465 (2008) 64-77 [1]) for (Al-Ti), Gong et al. (Int. J. Mater. Res. 95 (2004) 978-986 [2]) for (Al-V) and Saunders (COST 507, 2 (1998) 297-298 [3]) for (Ti-V). When combining the three binary systems and looking at the extrapolated ternary isothermal sections, it was found that there was a very large miscibility gap in the bcc phase. The origin of this miscibility gap was mainly the Al-V system and therefore it was decided to reassess this system. The Al-V system was reassessed according to available experimental data along with the enthalpies of formation of all compounds as well as the enthalpies of mixing for all terminal phases obtained by first-principles calculations based on the density functional theory. For the Al8V5 phase there are two different sets of data for the enthalpies of formation. These two sets are investigated in this work and it is found that the set not used by Gong et al. in their assessment of the Al-V binary system gives better extrapolations. The final description produced improved extrapolated ternary isothermal sections.

  • 16.
    Brusewitz Lindahl, Bonnie
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    The Al-Fe-Mn system revisited-An updated thermodynamic description using the most recent binaries2013In: Calphad, ISSN 0364-5916, E-ISSN 1873-2984, Vol. 43, p. 86-93Article in journal (Refereed)
    Abstract [en]

    The so-called TWinning Induced Plasticity (TWIP) steels have gained a lot of attention in the last couple of years due to their excellent mechanical properties; they show very high strength and are at the same time very ductile. The TWIP steels are austenitic and form mechanical twins under deformation. All TWIP steels have very high manganese content and a certain sub-group of these steels, lightweight steels with induced plasticity (so-called L-IP), also have high aluminum content. These steels are the lightweight versions of the TWIP steels and are therefore of high interest to the automotive industry. However, the grades existing today have too low yield strength. The yield strength can be improved by alloying and/or by precipitation hardening. Both these techniques require detailed insight on the thermodynamic properties of the alloy system in question. In this work, a thermodynamic reassessment of the entire Al-Fe-Mn system has been performed as a first step to describe the Fe-Al-C-Mn system, the core system for L-IP steels. All available experimental information has been taken into consideration and a set of data has been selected to be used in the optimization. The new thermodynamic description is based on the most recent thermodynamic descriptions of the constituent binaries and reproduces the experimental information in a satisfactory manner. This description, as opposed to previous descriptions has been optimized to fit experimental results in both the aluminum-rich part and the iron-manganese rich part of the system.

  • 17.
    Delandar, Arash Hosseinzadeh
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Gorbatov, O. I.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering. Applied Physics, Division of Materials Science, Department of Engineering Sciences and Mathematics, Luleå University of Technology, 97187 Luleå, Sweden; Laboratory for Mechanics of Gradient Nanomaterials, Nosov Magnitogorsk State Technical University, 455000 Magnitogorsk, Russia.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Gornostyrev, Y. N.
    Korzhavyi, Pavel A.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    End-member compounds of a 4-sublattice model of multicomponent BCC solid solutions2018In: Data in Brief, E-ISSN 2352-3409, Vol. 20, p. 1018-1022Article in journal (Refereed)
    Abstract [en]

    The article presents ab initio calculated properties (total energies, lattice parameters, and elastic properties) for the complete set of 1540 end-member compounds within a 4-sublattice model of Fe-based solid solutions. The compounds are symmetry-distinct cases of integral site occupancy for superstructure Y (space group #227, type LiMgPdSn) chosen to represent the ordered arrangements of solvent atoms (Fe), solute atoms (Fe, Mg, Al, Si, P, S, Mn, Ni, Cu), and vacancies (Va) on the sites of a body-centered cubic lattice. The model is employed in the research article “Ab-initio based search for late blooming phase compositions in iron alloys” (Hosseinzadeh et al., 2018) [1].

  • 18.
    Delandar, Arash Hosseinzadeh
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Gorbatov, O. I.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Multiscale Materials Modelling. Applied Physics, Division of Materials Science, Department of Engineering Sciences and Mathematics, Luleå University of Technology, 97187, Luleå, Sweden; Laboratory for Mechanics of Gradient Nanomaterials, Nosov Magnitogorsk State Technical University, 455000, Magnitogorsk, Russia.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Gornostyrev, Yu. N.
    Ryssland.
    Korzhavyi, Pavel A.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering. National University of Science and Technology ”MISiS”, 119049, Moscow, Russia.
    Ab-initio based search for late blooming phase compositions in iron alloys2018In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 509, p. 225-236Article in journal (Refereed)
    Abstract [en]

    We present a systematic analysis, based on ab initio calculations, of concentrated solute arrangements and precipitate phases in Fe-based alloys. The input data for our analysis are the calculated formation and interaction energies of point defects in the iron matrix, as well as the energies of ordered compounds that represent end-members in the 4-sublattice compound energy model of a multicomponent solid solution of Mg, Al, Si, P, S, Mn, Ni, and Cu elements and also vacancies in bcc Fe. The list of compounds also includes crystal structures obtained by geometric relaxation of the end-member compounds that in the cubic structure show weak mechanical instabilities (negative elastic constants) and also the G-phase Mn-6(Ni,Fe)(16)(Si,P)(7) having a complex cubic structure. A database of calculated thermodynamic properties (crystal structure, molar volume, enthalpy of formation, and elastic constants) of the most stable late-blooming-phase candidates is thus obtained. The results of this ab initio based theoretical analysis compare well with the recent experimental observations and predictions of thermodynamic calculations employing Calphad methodology.

  • 19.
    Dilner, David
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Kjellqvist, L.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Thermodynamic Assessment of the Fe-Ca-S, Fe-Mg-O and Fe-Mg-S Systems2016In: Journal of Phase Equilibria and Diffusion, ISSN 1547-7037, p. 1-16Article in journal (Refereed)
    Abstract [en]

    Thermodynamic descriptions of the Fe-Mg-O, Fe-Ca-S and Fe-Mg-S systems are all important in order to perform thermodynamic calculations related to the steelmaking process. The experimental information of many sulphur-containing systems, including Fe-Ca-S and Fe-Mg-S, is lacking and they are here thus approximated to behave similarly to the corresponding oxygen systems. This study presents a description of the Fe-Mg-O system in good agreement with experimental information. Additionally, descriptions of the Fe-Ca-S and Fe-Mg-S systems are presented. These descriptions may be reasonable estimations considering the lack of experimental information.

  • 20.
    Dilner, David
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Kjellqvist, Lina
    Mao, Huahai
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Improving Steel and Steelmaking - Computational Thermodynamics using a Sulphide and Oxide databaseManuscript (preprint) (Other academic)
  • 21.
    Dilner, David
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering. Scania CV AB, SE-15187 Sodertalje, Sweden..
    Kjellqvist, Lina
    Thermocalc Software AB, Rasundavagen 18, SE-16967 Solna, Sweden..
    Mao, Huahai
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering. Thermocalc Software AB, Rasundavagen 18, SE-16967 Solna, Sweden..
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Improving Steel and Steelmakingan Ionic Liquid Database for Alloy Process Design2018In: INTEGRATING MATERIALS AND MANUFACTURING INNOVATION, ISSN 2193-9764, Vol. 7, no 4, p. 195-201Article in journal (Refereed)
    Abstract [en]

    The latest development of a thermodynamic database is demonstrated with application examples related to the steelmaking process and steel property predictions. The database, TCOX, has comprehensive descriptions of the solution phases using ionic models. More specifically, applications involving sulphur and oxygen, separately as well as combined, are presented and compared with relevant multi-component experimental information found in the literature. The over-all agreement is good.

  • 22.
    Dilner, David
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Kjellqvist, Lina
    Mao, Huahai
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Improving Steel and Steelmaking—an Ionic Liquid Database for Alloy Process Design2018In: Integrating Materials and Manufacturing Innovation, ISSN 2193-9764, Vol. 7, p. 195-201Article in journal (Refereed)
    Abstract [en]

    The latest development of a thermodynamic database is demonstrated with application examples related to the steelmaking process and steel property predictions. The database, TCOX, has comprehensive descriptions of the solution phases using ionic models. More specifically, applications involving sulphur and oxygen, separately as well as combined, are presented and compared with relevant multi-component experimental information found in the literature. The over-all agreement is good.

  • 23.
    Dilner, David
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Lu, Qi
    Mao, Huahai
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics. Thermocalc Software AB, Sweden.
    Xu, Wei
    van der Zwaag, Sybrand
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Process-time Optimization of Vacuum Degassing Using a Genetic Alloy Design Approach2014In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 7, no 12, p. 7997-8011Article in journal (Refereed)
    Abstract [en]

    This paper demonstrates the use of a new model consisting of a genetic algorithm in combination with thermodynamic calculations and analytical process models to minimize the processing time during a vacuum degassing treatment of liquid steel. The model sets multiple simultaneous targets for final S, N, O, Si and Al levels and uses the total slag mass, the slag composition, the steel composition and the start temperature as optimization variables. The predicted optimal conditions agree well with industrial practice. For those conditions leading to the shortest process time the target compositions for S, N and O are reached almost simultaneously.

  • 24.
    Dilner, David
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Mao, Huahai
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Thermodynamic assessment of the Mn-S and Fe-Mn-S systems2015In: Calphad, ISSN 0364-5916, E-ISSN 1873-2984, Vol. 48, p. 95-105Article in journal (Refereed)
    Abstract [en]

    The Fe-Mn-S system is of great importance for the steelmaking process. As part of the work for the development of a large self-consistent thermodynamic database for such applications, the aim of the present assessment was to obtain a thermodynamic description of the Fe-Mn-S system using the ionic two-sublattice model for the liquid. Previous compatible descriptions of all unaries as well as two of the constituent binaries, Fe-Mn and Fe-S, were accepted. The third binary, Mn-S, was assessed in this work. Ternary parameters were optimised for the liquid, the alabandite, the pyrrhotite and the pyrite phases. Calculations using the present description agree well with experimental data.

  • 25.
    Dilner, David
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Thermodynamic description of the Fe-Ca-O-S system2017In: Calphad, ISSN 0364-5916, E-ISSN 1873-2984, Vol. 57, p. 118-125Article in journal (Refereed)
    Abstract [en]

    In an effort to describe sulphur in steels, particularly in steelmaking, a thermodynamic description of the Fe-Ca-O-S and its subsystems is presented. The ionic two-sublattice liquid model has been used to describe all liquids. For the Fe-O-S part of the system the calculations reproduce available experimental data well. Experimental data is scarce in the Ca-O-S system and in the quaternary and we to trust that the system is well reproduced by extrapolation by previously assessed sub-systems.

  • 26.
    Dilner, David
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Thermodynamic Description of the Fe-Ca-O-S systemManuscript (preprint) (Other academic)
  • 27. Frisk, K.
    et al.
    Selleby, Malin
    KTH, Superseded Departments, Materials Science and Engineering.
    The compound energy formalism: applications2001In: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 320, no 2, p. 177-188Article in journal (Refereed)
  • 28.
    Ghasemi, Masoomeh
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering. Lund University, Sweden.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Johansson, Jonas
    Thermodynamic assessment and binary nucleation modeling of Sn-seeded InGaAs nanowires2017In: Journal of Crystal Growth, ISSN 0022-0248, E-ISSN 1873-5002, Vol. 478, p. 152-158Article in journal (Refereed)
    Abstract [en]

    We have performed a thermodynamic assessment of the As-Ga-In-Sn system based on the CALculation of PHAse Diagram (CALPHAD) method. This system is part of a comprehensive thermodynamic database that we are developing for nanowire materials. Specifically, the As-Ga-In-Sn can be used in modeling the growth of GaAs, InAs, and InxGa(1-x)As nanowires assisted by Sn liquid seeds. In this work, the AsSn binary, the As-Ga-Sn, As-In-Sn, and Ga-In-Sn ternary systems have been thermodynamically assessed using the CALPHAD method. We show the relevant phase diagrams and property diagrams. They all show good agreement with experimental data. Using our optimized description we have modeled the nucleation of InxGa(1-x)As in the zinc blende phase from a Sn-based quaternary liquid alloy using binary nucleation modeling. We have linked the composition of the solid nucleus to the composition of the liquid phase. Eventually, we have predicted the critical size of the nucleus that forms from InAs and GaAs pairs under various conditions. We believe that our modeling can guide future experimental realization of Sn-seeded InxGa(1-x)As nanowires.

  • 29.
    Haglöf, Fredrik
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering. Sandvik Coromant R&D, S-12679 Stockholm, Sweden..
    Kaplan, B.
    Sandvik Coromant R&D, S-12679 Stockholm, Sweden..
    Norgren, S.
    Sandvik Coromant R&D, S-12679 Stockholm, Sweden.;Uppsala Univ, Angstrom Tribomat Grp, Appl Mat Sci, S-75121 Uppsala, Sweden..
    Blomqvist, A.
    Sandvik Coromant R&D, S-12679 Stockholm, Sweden..
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Experimental study of carbides in the Ti-Cr-C system2019In: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 54, no 19, p. 12358-12370Article in journal (Refereed)
    Abstract [en]

    The Ti-Cr-C system has been studied by producing samples within the MC-M3C2-M7C3 (M=Ti, Cr) and MC-M3C2-graphite equilibria. The main purpose was to determine the solubility of Cr in MC; however, the solubility of Ti in M3C2 and M7C3 was also of interest, as well as the C content in MC. Heat treatments have been performed at 1673 and 1773 K for 300 h. Thereafter, the phase compositions have been measured with energy-dispersive X-ray spectroscopy (EDS) and wavelength-dispersive X-ray spectroscopy (WDS). X-ray diffraction (XRD), in combination with Rietveld refinement, has been used to determine the lattice parameter for MC. Density functional theory (DFT) calculations were performed to estimate the lattice parameter for MC as a function of composition, and the Rietveld refined lattice parameters for MC have then been recalculated to compositions in order to verify the EDS measurements. The results show that the EDS and XRD measurements give equal results. One conclusion is that, with the current conditions, 300 h is a sufficient heat treatment time in order to reach thermodynamic equilibrium. The other main conclusion is that the solubility of Cr in MC, in general, was overestimated by previous studies due to too short heat treatment times, but also that the solubility is very temperature dependent, especially for the MC-M3C2-graphite equilibrium. This clear temperature dependence was not taken into account in the existing thermodynamic description found in the literature.

  • 30. Hallstedt, B.
    et al.
    Khvan, A. V.
    Lindahl, Bonnie B.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Liu, S.
    PrecHiMn-4—A thermodynamic database for high-Mn steels2017In: Calphad, ISSN 0364-5916, E-ISSN 1873-2984, Vol. 56, p. 49-57Article in journal (Refereed)
    Abstract [en]

    This paper concerns a Calphad database that was developed to describe precipitation of cubic carbides and nitrides (V, Nb and Ti) in high manganese steels and to describe phase equilibria in high manganese steels with high aluminium content. The database has also been shown to be useful for calculations on medium manganese steels and low-density steels with varying aluminium additions. Thus the database covers a significant fraction of the steels that are termed advanced high strength steels (AHSS) of the second and third generation. A number of systems were assessed (or reassessed) for the database, namely Fe–Mn–Al, Fe–Mn–C, Fe–Nb, Mn–Nb, Fe–Mn–Nb, Fe–Nb–V, Fe–Nb–C, Mn–Nb–C, Fe–Mn–Nb–C, Nb–N, Fe–Mn–Nb–N. The remaining systems were taken from published assessments. The database covers the elements Fe, Mn, Al, Si, V, Nb, Ti, C and N.

  • 31. Hillert, M.
    et al.
    Selleby, Malin
    KTH, Superseded Departments, Materials Science and Engineering.
    Point defects in B2 compounds2001In: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 329, no 02-jan, p. 208-213Article in journal (Refereed)
    Abstract [en]

    Point defects in B2 compounds are described with a model based on the formula (A,B,Va),(B,A,Va), and results are compared with previous results from two models based on combined defects and using the formulae (A,B), (B,A), and (A,Va)(1) (B,A)(1) The comparison is straight-forward close to the stoichiometric composition but not closer to the pure elements. Using the more general model, it is demonstrated that the fact that vacancies are the predominant defect in some B2 compounds with a small excess of B atoms depends primarily on interactions between next-nearest neighbours rather than on a high enthalpy of formation of the compound, as proposed earlier.

  • 32.
    Hillert, Mats
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Kjellqvist, Lina
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Mao, Huahai
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Sundman, Bo
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Parameters in the compound energy formalism for ionic systems2009In: Calphad, ISSN 0364-5916, E-ISSN 1873-2984, Vol. 33, no 1, p. 227-232Article in journal (Refereed)
    Abstract [en]

    The compound energy formalism, CEF, involves many model parameters. They are evaluated to give the best fit to the experimental information. The optimisation is simpler if less parameters need to be adjusted.The maximum number of independent parameters that can be evaluated depends on the information available. The best choice of parameters is first discussed for simple ionic substances with an internal variable, then for solutions of two or four such substances.

    To reduce the number of parameters, independent parameters are conveniently defined as combinations of primary model parameters. That may be possible when there is an internal variable,which can take only one value, the value that minimizes the Gibbs energy. Such combinations may be regarded as the true optimisation parameters and they may be used actively during an optimisation. The present discussion deals with substances with an internal variable and mixtures, which may have more than one internal variable.

    The conclusions apply equally well to non-ionic systems if the information is limited to stoichiometric compositions. The optimisation parameters should then be defined for stoichiometric overall compositions.

  • 33.
    Hillert, Mats
    et al.
    KTH, Superseded Departments, Materials Science and Engineering.
    Schwind, M.
    Selleby, Malin
    KTH, Superseded Departments, Materials Science and Engineering.
    Trapping of vacancies by rapid solidification2002In: Acta Materialia, ISSN 1359-6454, E-ISSN 1873-2453, Vol. 50, no 12, p. 3283-3291Article in journal (Refereed)
    Abstract [en]

    A model has been developed for the process of trapping of vacancies in rapid solidification of pure metals, which includes the effect of solute drag where vacancies play the role of solute. Within a reasonable range of parameter values it predicts that substantial trapping cannot occur unless the solidification velocity is 1 m/s or higher. It is demonstrated that the intrinsic mobility of the liquid/solid interface should not be evaluated without considering the effects of vacancy trapping and solute drag caused by vacancies. The model is applied to copper and unknown parameters are evaluated from information on the solidification velocity as a function of undercooling.

  • 34.
    Hillert, Mats
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Discussion of cementite layer formation and sooting2010In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 63, no 11, p. 1037-1040Article in journal (Refereed)
    Abstract [en]

    A thermodynamic explanation was recently proposed for the formation of massive layers of cementite without any graphite by gas carburization of steels at 550 degrees C if the gas contains NH(3). That explanation is now criticized. It is proposed that a kinetic factor, based on the difficulty of precipitating graphite inside a solid matrix, may contribute to the inhibition of metal dusting in the presence of NH3.

  • 35.
    Hillert, Mats
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Methods for storage of Gibbs energy data of substances2016In: Calphad, ISSN 0364-5916, E-ISSN 1873-2984, Vol. 53, p. 146-150Article in journal (Refereed)
    Abstract [en]

    There are two popular methods for storing Gibbs energy data for pure substances. They are inspired by Planck and by Lewis and Randall and may appear as very different but it will be demonstrated that they only differ by the choice of references. The derivation of functions to be stored will then be described and a crude but very simple method for extending them to 0. K by interpolation instead of extrapolation will be presented.

  • 36. Hillert, Mats
    et al.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Sundman, Bo
    An attempt to correct the quasichemical model2009In: Acta Materialia, ISSN 1359-6454, E-ISSN 1873-2453, Vol. 57, no 17, p. 5237-5244Article in journal (Refereed)
    Abstract [en]

    An attempt was made to correct the quasichemical model to avoid predictions of negative configurational entropy when long-range order is impossible as in liquids. The attempt was successful for negative interaction energies but for positive interaction energies the simplest possible variant of the model predicted two narrow miscibility gaps. It was not possible to improve this by adding regular solution parameters. However, using the next possible variant of the correction term these difficulties may be avoided.

  • 37.
    Kaplan, Bartek
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics. Sandvik Coromant R&D, Stockholm, Sweden.
    Blomqvist, Andreas
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Norgren, Susanne
    Thermodynamic analysis of the W-Co-Cr system supported by ab initio calculations and verified with quaternary data2015In: Calphad, ISSN 0364-5916, E-ISSN 1873-2984, Vol. 50, p. 59-67Article in journal (Refereed)
    Abstract [en]

    The present work aims at assessing the W-Co-Cr system with focus on including the ternary R-phase in the thermodynamic description. Enthalpies of formation at 0 K of all considered R-phase end-members are calculated using density functional theory and used in the assessment due to the scarceness of the experimental information. The resulting assessment is verified by comparing with recent experimental data in the W-Co-Cr-C quaternary system.

  • 38.
    Kaplan, Bartek
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Blomqvist, Andreas
    Sandvik Coromant R&D, Stockholm.
    Århammar, Cecilia
    Sandvik Coromant R&D, Stockholm.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Norgren, Susanne
    Sandvik Mining R&D, Stockholm.
    Structural Determination of (Cr,Co)7C32013Conference paper (Refereed)
    Abstract [en]

    Chromium is one of the most well-known WC grain growth inhibitors in cemented carbides. It is thus vital to understand and to be able to thermodynamically model the prevailing phase equilibria in the WC-Co-Cr system. To do this it is important that the lower order systems, such as the Co-Cr-C system, are correctly described. Previous investigations have shown that the M7C3 (M=Cr,Co,W) phase is the first carbide to form when Cr is added in excess to the WC+fcc-Co/liquid+graphite phase field. However, the exact structure of this phase has not been investigated and there are many proposed structures already for the binary Cr7C3 carbide, ranging from trigonal, via hexagonal to orthorhombic symmetry. Recent investigations show that the hexagonal structure belonging to the P63mc space group is the stable structure at 0 K. In the present study the binary Cr7C3 carbide and a mixed M7C3 carbide are investigated. The structures of both carbides and preferential positions for Co atoms in the mixed carbide are determined by XRD measurements in combination with ab initio calculations and Rietveld refinement.

  • 39.
    Kaplan, Bartek
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics. Sandvik Coromant R&D, Stockholm, Sweden.
    Joubert, Jean-Marc
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Norgren, Susanne
    Blomqvist, Andreas
    Neutron and X-ray diffraction study of (Cr,Co)7C3Manuscript (preprint) (Other academic)
  • 40.
    Kaplan, Bartek
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics. Sandvik Coromant RandD, Sweden .
    Markström, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics. Thermo-Calc Software AB, Sweden .
    Blomqvist, Andreas
    Sandvik Coromant R&D, Stockholm.
    Norgren, Susanne
    Sandvik Mining R&D, Stockholm.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Thermodynamic analysis of the Co-Cr-C system2014In: Calphad, ISSN 0364-5916, E-ISSN 1873-2984, Vol. 46, p. 226-236Article in journal (Refereed)
    Abstract [en]

    A reassessment of the thermodynamic description of the Co–Cr–C system was performed to take into account recent experimental information on the solubility of Co in Cr-based carbides. Density Functional Theory (DFT) calculations coupled with phonon calculations were performed to calculate the heat capacity and Gibbs energies of formation of stable and metastable carbides in the Co–Cr–C system as a function of temperature, within the limits of the Harmonic or the Quasi Harmonic Approximation. Resulting Gibbs energies were compared with earlier experimental studies and assessments, where calculated values for Cr23C6, Cr7C3 and Cr3C2 from the present work were seen to fall within the experimental scatter. The calculated heat capacity and Gibbs energy of formation as a function of temperature for the metastable Co3C2 compound together with recent experimental information was used in the evaluation of the thermodynamic parameters. As a result, the new and improved thermodynamic description accounts for the solubility of Co in M3C2 in contrast to previous descriptions, where this was neglected due to a complete lack of experimental information. Furthermore, a better representation of previously reported liquidus temperatures was achieved, without increasing the number of parameters in the liquid phase. Other relevant features of the phase diagram and thermochemical properties were also well represented.

  • 41.
    Kaplan, Bartek
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Markström, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Norgren, Susanne
    Sandvik Mining R&D, Stockholm.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Experimental Determination of the Solubility of Co in the Cr-Based Carbides Cr23C6, Cr7C3, and Cr3C22014In: Metallurgical and Materials Transactions. A, ISSN 1073-5623, E-ISSN 1543-1940, Vol. 45, no 11, p. 4820-4828Article in journal (Refereed)
    Abstract [en]

    Thermodynamic calculations based on the CALPHAD method are nowadays often applied in the design of new materials due to increasing demands on shorter lead times for development. However, such calculations rely heavily on the assessed thermodynamic descriptions, which in turn rely on the amount and quality of available experimental data, especially for binary and ternary sub-systems. The ternary Co-Cr-C system is an extremely important subsystem to, e.g., multi-component cemented carbide grades, such as W-Co-Cr-M-C (M = Ti,Ta,Nb,V,Zr,Hf), as well as Cr-containing Co-base alloys. In the case of the Co-Cr-C system, there is a lack of reliable data on the solubility of Co in Cr-carbides. Therefore, the present work concerns an experimental study of the solubility of Co in all three of the Cr-based carbides, i.e., Cr23C6, Cr7C3, and Cr3C2. This was done by synthesizing appropriate samples in the M7C3+M23C6+liquid and M7C3+M3C2+graphite three-phase fields. The results show that a recent thermodynamic description of the Co-Cr-C system is unable to reproduce the experimentally determined solubilities. Therefore, the present study provides important input for future alloy development and improvement of the thermodynamic description of the Co-Cr-C system.

  • 42.
    Kaplan, Bartek
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering. Sandvik Coromant RandD, Sweden.
    Norgren, Susanne
    Schwind, Martin
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Thermodynamic calculations and experimental verification in the WC-Co-Cr cemented carbide system2015In: International Journal of Refractory Metals and Hard Materials, ISSN 0263-4368, Vol. 48, p. 257-262Article in journal (Refereed)
    Abstract [en]

    Tungsten carbide and cobalt have always been, and still are, the foundation of cemented carbides. Modem grades include several other alloying elements, apart from just WC-Co, added for several different purposes. For example, by adding chromium it is possible to produce extremely fine grained grades compared to straight WC-Co grades and thus the freedom to tailor the properties of the material is increased. By applying thermodynamic calculations it is possible to design the material and also avoid some of the costly trial-and-error procedures. However, there is also a need for experimental verification in order to have confidence in the predictive calculations. The present work concerns the application of thermodynamic calculations to some relevant compositions together with experimental verification in the WC-Co-Cr system. Special focus is given to the limiting conditions for precipitation of unwanted phases with regards to the Cr-content in the binder, C-content and melting temperatures. No regard is taken to the presumable Cr-solubility in the WC phase itself.

  • 43.
    Kaplan, Bartek
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering. Sandvik Coromant R&D, Stockholm, Sweden.
    Norgren, Susanne
    Schwind, Martin
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Thermodynamic calculations and experimental verification in the WC-Co-Cr cemented carbide system (Reprint of Int. Journal of Refractory Metals and Hard Materials vol 48, pg 257-262, 2015)2015In: INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS, ISSN 0263-4368, Vol. 49, p. 400-405Article in journal (Refereed)
    Abstract [en]

    Tungsten carbide and cobalt have always been, and still are, the foundation of cemented carbides. Modem grades include several other alloying elements, apart from just WC-Co, added for several different purposes. For example, by adding chromium it is possible to produce extremely fine grained grades compared to straight WC-Co grades and thus the freedom to tailor the properties of the material is increased. By applying thermodynamic calculations it is possible to design the material and also avoid some of the costly trial-and-error procedures. However, there is also a need for experimental verification in order to have confidence in the predictive calculations. The present work concerns the application of thermodynamic calculations to some relevant compositions together with experimental verification in the WC-Co-Cr system. Special focus is given to the limiting conditions for precipitation of unwanted phases with regards to the Cr-content in the binder, C-content and melting temperatures. No regard is taken to the presumable Cr-solubility in the WC phase itself.

  • 44.
    Kjellqvist, Lina
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Adding C to the thermodynamic description of the Cr-Fe-Ni-O system2009In: Calphad, ISSN 0364-5916, E-ISSN 1873-2984, Vol. 33, no 2, p. 393-397Article in journal (Refereed)
    Abstract [en]

    The Cr–Fe–Ni–O system has been studied in an earlier work with the intention to thermodynamically describe the influence of oxygen in highly alloyed steels. The aim of this study was to also include carbon in this description, with an emphasis on the modelling of the liquid phase. The liquid phase is assessed using the ionic two-sublattice model and good agreement between calculated and experimental data is achieved in the C–Fe–O system. In the C–Ni–O system the calculated solubility of oxygen in the liquid phase is about two orders of magnitude lower than the experimental data. Due to the very low oxygen solubility in liquid C–Ni, no ternary parameter could have any effect on the calculated solubility. By comparing with other oxide bearing ternary systems, it is suggested that the thermodynamic calculations probably give more reliable results than the experimental measurements when the oxygen solubility is very low. For the C–Cr–O system, no experimental information is available. The interaction parameters in the liquid phase were therefore set to zero.

  • 45.
    Kjellqvist, Lina
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Thermodynamic assessment of the Cr-Mn-O system2010In: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 507, no 1, p. 84-92Article in journal (Refereed)
    Abstract [en]

    The C-Cr-Fe-Ni-O and Fe-Mn-O systems have been studied earlier with the intention to thermodynamically describe the influence of oxygen on high alloyed steels. In this study the ternary Cr-Mn-O system is assessed. The liquid phase is assessed using the ionic two-sublattice model. Good agreement between calculated and experimental values is achieved.

  • 46.
    Kjellqvist, Lina
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Thermodynamic assessment of the Fe-Mn-O system2010In: Journal of Phase Equilibria and Diffusion, ISSN 1547-7037, Vol. 31, no 2, p. 113-134Article in journal (Refereed)
    Abstract [en]

    The C-Cr-Fe-Ni-O system has recently been studied with the intention to thermodynamically describe the influence of oxygen on high alloyed steels. In this study the ternary Fe-Mn-O system is assessed and part of the binary Mn-O system is reassessed. α- and β-hausmannite (Mn3O4) were earlier described as stoichiometric phases, but are here described using the compound energy formalism with a four sublattice model to be consistent with the preceding study of the Cr-Fe-Ni-O spinel. The liquid phase is assessed using the ionic two-sublattice model. Good agreement between calculated and experimental values is achieved.

  • 47.
    Kjellqvist, Lina
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Thermodynamic assessment of the Mn-Ni-O system2010In: International Journal for Materials Research Zeitschrift für Metallkunde, ISSN 1862-5282, Vol. 101, no 10, p. 1222-1231Article in journal (Refereed)
    Abstract [en]

    The C-Cr-Fe-Ni-O system has recently been studied with the intention to thermodynamically describe the influence of oxygen on high alloyed steels. In this study the ternary Mn-Ni-O system is assessed. The liquid phase is assessed using the ionic two-sublattice model. Good agreement between calculated and experimental values are achieved.

  • 48.
    Kjellqvist, Lina
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Selleby, Malin
    Sundman, Bo
    Thermodynamic assessments of the Al2O3-TiO2, CaO-TiO2, FeO-TiO2, Fe2O3-TiO2, MgO-TiO2 and MnO-TiO2 systemsManuscript (Other academic)
  • 49.
    Kjellqvist, Lina
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Sundman, Bo
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Thermodynamic modelling of the Cr-Fe-Ni-O system2008In: Calphad, ISSN 0364-5916, E-ISSN 1873-2984, Vol. 32, no 3, p. 577-592Article in journal (Refereed)
    Abstract [en]

    There is a need to describe the influence of oxygen on high alloyed steels, both regarding oxidation processes–as in the formation of oxide layers–and regarding steel/slag processes in a metallurgical context. As a first step and in order to be able to perform calculations and simulations on these different processes, the thermodynamic properties need to be described, as done for the Cr–Fe–Ni–O system. Previous attempts to describe this system has resulted in an inconsistent description, more specifically concerning the spinel phase. The aim of the present study is to obtain a consistent thermodynamic database for the Cr–Fe–Ni–O system with an emphasis on the modelling of the spinel phase. The solid phases are described using the compound energy formalism and the metallic and ionized liquid is modelled using the ionic two-sublattice model. A complete list of all binary and higher order parameters is included.

  • 50.
    Korzhavyi, Pavel A.
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Sundman, Bo
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Johansson, Börje
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Atomic, electronic, and magnetic structure of iron-based sigma-phases2005In: Integrative and Interdisciplinary Aspects of Intermetallics / [ed] MIlls, MJ; Inui, H; Clemens, H; Fu, CL, WARRENDALE: MATERIALS RESEARCH SOCIETY , 2005, Vol. 842, p. 517-522Conference paper (Refereed)
    Abstract [en]

    A combination of ab initio total energy calculations with Calphad approach is applied to model the site occupancy and thermodynamic properties of the Fe-Cr, Co-Cr, Fe-V, and Fe-Mo binary sigma-phases as a function of composition and temperature. For each binary sigma-phase the parameters of the model are the ab initio calculated total energies of so-called end-member compounds, which represent all the 2(5)=32 variants of complete occupancy of each of the five crystallographically inequivalent sites by one or the other alloy component, The paramagnetic state of the sigma-phases has been taken into account within the disordered local moment approach. The Fe and Co atoms are found to retain high spin moments when they occupy high-coordination-number sites in the structure. Using our model we were able to reproduce the experimentally observed site occupancy in the FeCr sigma-phase. The calculated site occupancies in the Co-Cr, Fe-V, and Fe-Mo sigma-phases are also presented and discussed.

12 1 - 50 of 98
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf