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  Subjects -> COMPUTER SCIENCE (Total: 2011 journals)
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COMPUTER SCIENCE (1172 journals)                  1 2 3 4 5 6 | Last

Showing 1 - 200 of 872 Journals sorted alphabetically
3D Printing and Additive Manufacturing     Full-text available via subscription   (Followers: 15)
Abakós     Open Access   (Followers: 4)
ACM Computing Surveys     Hybrid Journal   (Followers: 24)
ACM Journal on Computing and Cultural Heritage     Hybrid Journal   (Followers: 9)
ACM Journal on Emerging Technologies in Computing Systems     Hybrid Journal   (Followers: 13)
ACM Transactions on Accessible Computing (TACCESS)     Hybrid Journal   (Followers: 4)
ACM Transactions on Algorithms (TALG)     Hybrid Journal   (Followers: 16)
ACM Transactions on Applied Perception (TAP)     Hybrid Journal   (Followers: 6)
ACM Transactions on Architecture and Code Optimization (TACO)     Hybrid Journal   (Followers: 9)
ACM Transactions on Autonomous and Adaptive Systems (TAAS)     Hybrid Journal   (Followers: 7)
ACM Transactions on Computation Theory (TOCT)     Hybrid Journal   (Followers: 12)
ACM Transactions on Computational Logic (TOCL)     Hybrid Journal   (Followers: 3)
ACM Transactions on Computer Systems (TOCS)     Hybrid Journal   (Followers: 18)
ACM Transactions on Computer-Human Interaction     Hybrid Journal   (Followers: 15)
ACM Transactions on Computing Education (TOCE)     Hybrid Journal   (Followers: 6)
ACM Transactions on Design Automation of Electronic Systems (TODAES)     Hybrid Journal   (Followers: 2)
ACM Transactions on Economics and Computation     Hybrid Journal  
ACM Transactions on Embedded Computing Systems (TECS)     Hybrid Journal   (Followers: 4)
ACM Transactions on Information Systems (TOIS)     Hybrid Journal   (Followers: 21)
ACM Transactions on Intelligent Systems and Technology (TIST)     Hybrid Journal   (Followers: 8)
ACM Transactions on Interactive Intelligent Systems (TiiS)     Hybrid Journal   (Followers: 4)
ACM Transactions on Multimedia Computing, Communications, and Applications (TOMCCAP)     Hybrid Journal   (Followers: 10)
ACM Transactions on Reconfigurable Technology and Systems (TRETS)     Hybrid Journal   (Followers: 7)
ACM Transactions on Sensor Networks (TOSN)     Hybrid Journal   (Followers: 9)
ACM Transactions on Speech and Language Processing (TSLP)     Hybrid Journal   (Followers: 10)
ACM Transactions on Storage     Hybrid Journal  
ACS Applied Materials & Interfaces     Full-text available via subscription   (Followers: 25)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 3)
Acta Universitatis Cibiniensis. Technical Series     Open Access  
Ad Hoc Networks     Hybrid Journal   (Followers: 11)
Adaptive Behavior     Hybrid Journal   (Followers: 11)
Advanced Engineering Materials     Hybrid Journal   (Followers: 26)
Advanced Science Letters     Full-text available via subscription   (Followers: 9)
Advances in Adaptive Data Analysis     Hybrid Journal   (Followers: 7)
Advances in Artificial Intelligence     Open Access   (Followers: 16)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 6)
Advances in Computational Mathematics     Hybrid Journal   (Followers: 18)
Advances in Computer Science : an International Journal     Open Access   (Followers: 15)
Advances in Computing     Open Access   (Followers: 2)
Advances in Data Analysis and Classification     Hybrid Journal   (Followers: 52)
Advances in Engineering Software     Hybrid Journal   (Followers: 27)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 11)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 27)
Advances in Human-Computer Interaction     Open Access   (Followers: 21)
Advances in Materials Sciences     Open Access   (Followers: 16)
Advances in Operations Research     Open Access   (Followers: 12)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7)
Advances in Porous Media     Full-text available via subscription   (Followers: 5)
Advances in Remote Sensing     Open Access   (Followers: 40)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Advances in Technology Innovation     Open Access   (Followers: 4)
AEU - International Journal of Electronics and Communications     Hybrid Journal   (Followers: 8)
African Journal of Information and Communication     Open Access   (Followers: 8)
African Journal of Mathematics and Computer Science Research     Open Access   (Followers: 4)
Air, Soil & Water Research     Open Access   (Followers: 9)
AIS Transactions on Human-Computer Interaction     Open Access   (Followers: 6)
Algebras and Representation Theory     Hybrid Journal   (Followers: 1)
Algorithms     Open Access   (Followers: 11)
American Journal of Computational and Applied Mathematics     Open Access   (Followers: 5)
American Journal of Computational Mathematics     Open Access   (Followers: 4)
American Journal of Information Systems     Open Access   (Followers: 5)
American Journal of Sensor Technology     Open Access   (Followers: 4)
Anais da Academia Brasileira de Ciências     Open Access   (Followers: 2)
Analog Integrated Circuits and Signal Processing     Hybrid Journal   (Followers: 7)
Analysis in Theory and Applications     Hybrid Journal   (Followers: 1)
Animation Practice, Process & Production     Hybrid Journal   (Followers: 5)
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Data Science     Hybrid Journal   (Followers: 11)
Annals of Mathematics and Artificial Intelligence     Hybrid Journal   (Followers: 12)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of Software Engineering     Hybrid Journal   (Followers: 13)
Annual Reviews in Control     Hybrid Journal   (Followers: 6)
Anuario Americanista Europeo     Open Access  
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applied and Computational Harmonic Analysis     Full-text available via subscription   (Followers: 1)
Applied Artificial Intelligence: An International Journal     Hybrid Journal   (Followers: 13)
Applied Categorical Structures     Hybrid Journal   (Followers: 2)
Applied Clinical Informatics     Hybrid Journal   (Followers: 2)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 12)
Applied Computer Systems     Open Access   (Followers: 2)
Applied Informatics     Open Access  
Applied Mathematics and Computation     Hybrid Journal   (Followers: 33)
Applied Medical Informatics     Open Access   (Followers: 10)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Soft Computing     Hybrid Journal   (Followers: 15)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 5)
Architectural Theory Review     Hybrid Journal   (Followers: 3)
Archive of Applied Mechanics     Hybrid Journal   (Followers: 5)
Archive of Numerical Software     Open Access  
Archives and Museum Informatics     Hybrid Journal   (Followers: 137)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 4)
Artifact     Hybrid Journal   (Followers: 2)
Artificial Life     Hybrid Journal   (Followers: 7)
Asia Pacific Journal on Computational Engineering     Open Access  
Asia-Pacific Journal of Information Technology and Multimedia     Open Access   (Followers: 1)
Asian Journal of Computer Science and Information Technology     Open Access  
Asian Journal of Control     Hybrid Journal  
Assembly Automation     Hybrid Journal   (Followers: 2)
at - Automatisierungstechnik     Hybrid Journal   (Followers: 1)
Australian Educational Computing     Open Access   (Followers: 1)
Automatic Control and Computer Sciences     Hybrid Journal   (Followers: 4)
Automatic Documentation and Mathematical Linguistics     Hybrid Journal   (Followers: 5)
Automatica     Hybrid Journal   (Followers: 11)
Automation in Construction     Hybrid Journal   (Followers: 6)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 9)
Basin Research     Hybrid Journal   (Followers: 5)
Behaviour & Information Technology     Hybrid Journal   (Followers: 52)
Biodiversity Information Science and Standards     Open Access  
Bioinformatics     Hybrid Journal   (Followers: 287)
Biomedical Engineering     Hybrid Journal   (Followers: 15)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 14)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 18)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 34)
Briefings in Bioinformatics     Hybrid Journal   (Followers: 47)
British Journal of Educational Technology     Hybrid Journal   (Followers: 139)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 10)
c't Magazin fuer Computertechnik     Full-text available via subscription   (Followers: 2)
CALCOLO     Hybrid Journal  
Calphad     Hybrid Journal  
Canadian Journal of Electrical and Computer Engineering     Full-text available via subscription   (Followers: 14)
Capturing Intelligence     Full-text available via subscription  
Catalysis in Industry     Hybrid Journal   (Followers: 1)
CEAS Space Journal     Hybrid Journal   (Followers: 2)
Cell Communication and Signaling     Open Access   (Followers: 2)
Central European Journal of Computer Science     Hybrid Journal   (Followers: 5)
CERN IdeaSquare Journal of Experimental Innovation     Open Access   (Followers: 1)
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 14)
ChemSusChem     Hybrid Journal   (Followers: 7)
China Communications     Full-text available via subscription   (Followers: 7)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
CIN Computers Informatics Nursing     Full-text available via subscription   (Followers: 11)
Circuits and Systems     Open Access   (Followers: 15)
Clean Air Journal     Full-text available via subscription   (Followers: 2)
CLEI Electronic Journal     Open Access  
Clin-Alert     Hybrid Journal   (Followers: 1)
Cluster Computing     Hybrid Journal   (Followers: 1)
Cognitive Computation     Hybrid Journal   (Followers: 4)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 14)
Communication Methods and Measures     Hybrid Journal   (Followers: 12)
Communication Theory     Hybrid Journal   (Followers: 20)
Communications Engineer     Hybrid Journal   (Followers: 1)
Communications in Algebra     Hybrid Journal   (Followers: 3)
Communications in Partial Differential Equations     Hybrid Journal   (Followers: 3)
Communications of the ACM     Full-text available via subscription   (Followers: 55)
Communications of the Association for Information Systems     Open Access   (Followers: 18)
COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering     Hybrid Journal   (Followers: 3)
Complex & Intelligent Systems     Open Access   (Followers: 1)
Complex Adaptive Systems Modeling     Open Access  
Complex Analysis and Operator Theory     Hybrid Journal   (Followers: 2)
Complexity     Hybrid Journal   (Followers: 6)
Complexus     Full-text available via subscription  
Composite Materials Series     Full-text available via subscription   (Followers: 9)
Computación y Sistemas     Open Access  
Computation     Open Access  
Computational and Applied Mathematics     Hybrid Journal   (Followers: 2)
Computational and Mathematical Methods in Medicine     Open Access   (Followers: 2)
Computational and Mathematical Organization Theory     Hybrid Journal   (Followers: 2)
Computational and Structural Biotechnology Journal     Open Access   (Followers: 2)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Astrophysics and Cosmology     Open Access   (Followers: 1)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 11)
Computational Chemistry     Open Access   (Followers: 2)
Computational Cognitive Science     Open Access   (Followers: 2)
Computational Complexity     Hybrid Journal   (Followers: 4)
Computational Condensed Matter     Open Access  
Computational Ecology and Software     Open Access   (Followers: 9)
Computational Economics     Hybrid Journal   (Followers: 9)
Computational Geosciences     Hybrid Journal   (Followers: 15)
Computational Linguistics     Open Access   (Followers: 22)
Computational Management Science     Hybrid Journal  
Computational Mathematics and Modeling     Hybrid Journal   (Followers: 8)
Computational Mechanics     Hybrid Journal   (Followers: 4)
Computational Methods and Function Theory     Hybrid Journal  
Computational Molecular Bioscience     Open Access   (Followers: 2)
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computational Particle Mechanics     Hybrid Journal   (Followers: 1)
Computational Research     Open Access   (Followers: 1)
Computational Science and Discovery     Full-text available via subscription   (Followers: 2)
Computational Science and Techniques     Open Access  
Computational Statistics     Hybrid Journal   (Followers: 14)
Computational Statistics & Data Analysis     Hybrid Journal   (Followers: 30)
Computer     Full-text available via subscription   (Followers: 91)
Computer Aided Surgery     Hybrid Journal   (Followers: 5)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 8)
Computer Communications     Hybrid Journal   (Followers: 10)
Computer Engineering and Applications Journal     Open Access   (Followers: 5)
Computer Journal     Hybrid Journal   (Followers: 9)
Computer Methods in Applied Mechanics and Engineering     Hybrid Journal   (Followers: 22)
Computer Methods in Biomechanics and Biomedical Engineering     Hybrid Journal   (Followers: 12)
Computer Methods in the Geosciences     Full-text available via subscription   (Followers: 2)
Computer Music Journal     Hybrid Journal   (Followers: 18)
Computer Physics Communications     Hybrid Journal   (Followers: 6)
Computer Science - Research and Development     Hybrid Journal   (Followers: 8)
Computer Science and Engineering     Open Access   (Followers: 19)
Computer Science and Information Technology     Open Access   (Followers: 13)
Computer Science Education     Hybrid Journal   (Followers: 14)
Computer Science Journal     Open Access   (Followers: 22)

        1 2 3 4 5 6 | Last

Journal Cover Calphad
  [SJR: 1.116]   [H-I: 44]   [0 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0364-5916
   Published by Elsevier Homepage  [3123 journals]
  • Thermodynamics of the ZnSO4-H2SO4-H2O system
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): T. Vielma, J. Salminen, U. Lassi
      Internally consistent set of thermodynamic parameters was derived for the binary ZnSO4–H2O -system using the CALPHAD method. Available data on water activity, EMF measurements, solubility and heat of solution and dilution measurements was reviewed. Additional parameters for the ternary ZnSO4–H2SO4–H2O system were derived based on the available solubility and boiling point data. Solubility of zinc sulfate was predicted successfully under conditions relevant in hydrometallurgical processing of zinc, and even up to 15molkg−1 sulfuric acid solutions. Temperature dependent Pitzer parameters for the binary and ternary systems are reported.

      PubDate: 2018-02-05T17:03:07Z
       
  • Critical assessment and thermodynamic modeling of the Cu-As system
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): Denis Shishin, Evgueni Jak
      Thermodynamic assessment and modeling of the Cu-As system are presented. The experimental dataset includes phase equilibrium data, activity measurements, heat contents, enthalpies of formation and mixing. The liquid phase and two non-stoichiometric copper arsenide solid solutions are developed within the framework of the Modified Quasichemical Model (MQM) in pair approximation. It is demonstrated that the unconventional choice of model for solid solution phases is beneficial for this particular system. The resulting set of model parameters will be a part of a large multicomponent thermodynamic database. It is aimed for predictions of phase equilibria, heat balance and distribution of elements in arsenic-containing chemical systems in pyrometallurgical copper and lead industrial operations.

      PubDate: 2018-02-05T17:03:07Z
       
  • A thermodynamic description of data for pure Pb from 0K using the expanded
           
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): A.V. Khvan, A.T. Dinsdale, I.A. Uspenskaya, M. Zhilin, T. Babkina, A.M. Phiri
      Thermodynamic data for the crystalline and liquid phases of pure lead were critically assessed. A thermodynamic description was obtained using an extended Einstein model for the crystalline phase and a two state model for the liquid phase. The assessment was carried out through careful analysis of the experimental data published in the scientific literature. Additional measurements using enthalpy drop were also carried out in the present work to remove ambiguities in published experimental data.

      PubDate: 2018-02-05T17:03:07Z
       
  • Experimental and thermodynamic study of the influence of the base elements
           on the carbides natures in {Ni,Co}-based {25Cr, 0.4C, 6Ta}-containing
           alloys
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): Patrice Berthod, Zohra Himeur
      Primary carbides may be important for the high temperature strength of polycrystalline Cr-rich cast alloys. TaC are among the best carbides for this role. Their presence depends on the base elements of the alloys. This dependence is here studied in the case of a series of Cr-rich alloys based on Ni and/or Co and containing Ta and C in equal molar fractions. Real alloys were cast and exposed at 1400K and 1510K, and their as-cast and aged microstructures were characterized. In parallel thermodynamic calculations using Thermo-Calc and a home-made database were carried out. It appears that TaC is the single carbide present in the alloy stabilized at high temperature only if the Co content is higher than the Ni one. Discrepancies appeared between calculations and the experimental results, showing that the used database must be improved. The experimental part of this work provides microstructures data which can be used to test databases and to enrich them if necessary.

      PubDate: 2018-02-05T17:03:07Z
       
  • Phase diagrams and thermochemical modeling of salt lake brine systems.
           III. Li2SO4+H2O, Na2SO4+H2O, K2SO4+H2O, MgSO4+H2O and CaSO4+H2O systems
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): Dongdong Li, Dewen Zeng, Xia Yin, Dandan Gao
      This paper is part of a series of studies on the development of a multi-temperature thermodynamically consistent model for salt lake brine systems. Under the comprehensive thermodynamic framework proposed in our previous study, the thermodynamic and phase equilibria properties of the sulfate binary systems (i.e., Li2SO4 + H2O, Na2SO4 + H2O, K2SO4 + H2O, MgSO4 + H2O and CaSO4 + H2O) were simulated using the Pitzer-Simonson-Clegg (PSC) model. Various type of thermodynamic properties (i.e., water activity, osmotic coefficient, mean ionic activity coefficient, enthalpy of dilution and solution, relative apparent molar enthalpy, heat capacity of aqueous phase and solid phases) were collected and fitted to the model equations. The thermodynamic properties of these systems can be well reproduced or predicted using the obtained model parameters. Comparisons with the experimental or model values in literature indicate that the model parameters determined in this study can describe all of the thermodynamic and phase equilibria properties of these binary sulfate systems from infinite dilution to saturation and freezing point temperature to approx. 500K.

      PubDate: 2018-02-05T17:03:07Z
       
  • HitDIC: A free-accessible code for high-throughput determination of
           interdiffusion coefficients in single solution phase
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): Jing Zhong, Weimin Chen, Lijun Zhang
      In this paper, a free-accessible code for High-throughput Determination of Interdiffusion Coefficients (HitDIC, https://hitdic.com/) based on the numerical inverse method is introduced. HitDIC is developed to robotize the procedures to retrieve the reliable composition-dependent interdiffusivities from the experimental composition profiles of single or multiple diffusion couples by minimizing the misfit between the experimental and model-predicted compositions profiles. The code is an efficient C++ implementation and provided as a free-accessible one, as well as demos and assistant toolkits. The underlying physics and mathematics of the modules of HitDIC, (i.e., database, simulation, error and minimization modules) are also demonstrated. Such an implementation is further proved to be feasible and reliable according to the results and discussion of the benchmarks and real cases. Moreover, some hints for the usage of HitDIC are also given.
      Graphical abstract image Highlights fx1

      PubDate: 2018-02-05T17:03:07Z
       
  • Measurement of phase equilibria in Ti-Co-Pt ternary system
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): K. Hu, X.M. Huang, J. Lu, H.S. Liu, G.M. Cai, Z.P. Jin
      Phase equilibria in the Ti-Co-Pt ternary system were measured through diffusion triple and alloy sampling. Based on the results from Electron Probe Microanalysis (EPMA) and X-ray diffraction (XRD) techniques, the isothermal sections of the Ti-Co-Pt system were constructed, which consist of 16 and 13 three-phased regions at 973 and 1173K, respectively. A new ternary phase τ was detected, which contains 23.6–29.9at% Pt at 973K and 27.4–40.1at% Pt at 1173K. Furthermore, an invariant reaction between 973 and 1173K was deduced, i.e. τ + Ti4Pt3 ↔ Ti3Pt + TiPt. By the way, the solubilities of Pt mainly substituting for Co in TiCo and TiCo3 respectively increase from 22.4at% and 26.1at% at 973K to 23.8at% and 33.1at% at 1173K.

      PubDate: 2018-02-05T17:03:07Z
       
  • Modified embedded-atom method interatomic potentials for pure Zn and Mg-Zn
           binary system
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): Hyo-Sun Jang, Kyeong-Min Kim, Byeong-Joo Lee
      Interatomic potentials for pure Zn and Mg–Zn binary system have been developed on the basis of the second nearest-neighbor modified embedded-atom method formalism. The potentials describe fundamental material properties of pure Zn (bulk, defect, and thermal properties) reasonably and reproduce the alloy behavior (thermodynamic, structural, and elastic properties of compounds and solution phases) of Mg-Zn alloys well in good agreement with experiments, first-principles and CALPHAD. The applicability of the developed potentials to atom-scale investigations on the slip behavior of Mg-Zn alloys is also demonstrated by showing that the calculated effects of Zn on the general stacking fault energy on the basal, prismatic and pyramidal planes are consistent with first-principles calculations.

      PubDate: 2018-02-05T17:03:07Z
       
  • Thermodynamic modeling of Ag – Cu nanoalloy phase diagram
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): Mohammad Amin Jabbareh, Fatemeh Monji
      Ag – Cu nanoparticles has been attracted a considerable attention due to their potential to use as catalysts, sensors and nano – solders. It is well known that the alloy nanoparticles have different phase stabilities than those observed in the bulk systems. Previous calculated results on phase stability of Ag – Cu nanoparticles showed relatively large differences with reported experimental data. Using recently modified CALPHAD type thermodynamic model, we reassess the phase diagram of Ag – Cu nanoalloy. Effect of particle size has been discussed. The results compared with the experimental and calculated data from the literature. In comparison with previous calculated phase diagrams, calculated phase diagram in this work shows better agreements with the experimental data.
      Graphical abstract image

      PubDate: 2018-02-05T17:03:07Z
       
  • Thermodynamic optimizations of the Nd-Sn and Sn-Tb systems
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): S.L. Wang, X.H. Su, S.S. Li, C.Y. Fu, Y.H. Guo, Y.X. Huang, D.H. Xiang, C.P. Wang, X.J. Liu
      The thermodynamic optimizations of the Nd-Sn and Sn-Tb binary systems were carried out by means of the Calculation of Phase Diagram (CALPHAD) method on the basis of the available experimental data including the thermodynamic properties and phase equilibria. The Gibbs free energies of the liquid, bcc, bct, dhcp and hcp phases were described by the substitutional solution model with the Redlich-Kister equation, while all of the intermetallic compounds (Nd5Sn3, Nd5Sn4, Nd11Sn10, NdSn, Nd3Sn5, NdSn2, Nd3Sn7, Nd2Sn5, NdSn3, Sn3Tb, βSn7Tb3, αSn7Tb3, Sn2Tb, Sn5Tb4, SnTb4, Sn10Tb11, Sn4Tb5 and Sn3Tb5) were described by the sublattice model. A set of self-consistent thermodynamic parameters of each phase in the Nd-Sn and Sn-Tb binary systems has been obtained, and the calculated results are in good agreement with the available experimental data.

      PubDate: 2018-02-05T17:03:07Z
       
  • Thermodynamic modeling of the Al-C-Mn system supported by ab initio
           calculations
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): Weisen Zheng, Xiao-Gang Lu, Huahai Mao, Yanlin He, Malin Selleby, Lin Li, John Ågren
      A CALPHAD-type thermodynamic assessment of the Al-C-Mn system was carried out in the present work. Special attention was paid to the ternary κ-phase with the aid of ab initio calculations. The enthalpies of formation at 0 K of all end-members of the κ phase were derived from the ab initio calculations and utilized in the present optimization. The κ phase was modeled as an ordered form of the fcc structure for the substitutional sub-lattices, employing the following formula within the framework of compound energy formalism: (Al,Mn)0.25(Al,Mn)0.25(Al,Mn)0.25(Al,Mn)0.25(C,Va)0.25. With the present optimized model parameters, the wide homogeneity range of the κ phase was reproduced satisfactorily. Comparison between the predicted and measured phase equilibria as well as the ab initio calculation results validates the present optimized model parameters.

      PubDate: 2018-02-05T17:03:07Z
       
  • A CALPHAD assessment of the Al–Mn–C system supported by ab
           initio calculations
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): Florian Tang, Dimitri Bogdanovski, Irina Bajenova, Alexandra Khvan, Richard Dronskowski, Bengt Hallstedt
      frequently toggled from 1The Al–Mn–C ternary system has been thermodynamically evaluated using the CALPHAD method. Published data on phase equilibria have been critically examined and used to optimize the model parameters. The phase model for the κ AlMn3C phase (E21) has been changed to (Al,Mn)1(Al,Mn)3(C,Va)1 for improved reproduction of stability ranges and phase equilibria at 1100 °C and 1200 °C. The solid solution phase parameters of γ -Mn, ε -AlMn, ε -Mn4C have been adjusted to reproduce experimental ternary phase equilibria. Density functional theory-based ab initio calculations of enthalpies of formation at 0 K were performed to guide the modeling of the κ phase and elucidate general energetic trends. Reasonable liquidus temperatures were achieved by adjustments to the stability of the liquid phase. The Mn5C2 phase model was extended to Mn5(C,Al)2 which allows aluminium on the carbon sublattice. The CALPHAD calculations were performed with the optimized set of parameters and compared with the available experimental data and changes to previous work were elucidated.

      PubDate: 2018-02-05T17:03:07Z
       
  • Revised thermodynamic description of the Fe-Cr system based on an improved
           sublattice model of the σ phase
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): Aurélie Jacob, Erwin Povoden-Karadeniz, Ernst Kozeschnik
      The Fe-Cr system is re-assessed, focusing on an improved modeling of σ phase. The three sublattice model (Cr,Fe)10(Cr,Fe)4(Cr,Fe)16 is parameterized to model the σ phase, solving discrepancies between computed and experimental site fractions of previous descriptions. Taking into account relative metastability trends of end-member compounds from first-principles analysis, only two additional interaction parameters of the σ-FeCr description were required for the reproduction of the chemical structure, thermodynamic properties and phase boundaries.

      PubDate: 2017-12-27T12:27:34Z
       
  • A thermodynamic description of the U−Ti−Zr system
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): Yinping Zeng, Peng Zhou, Yong Du, Wenlin Mo, Bin Bai, Xiaolin Wang, Jingrui Zhao
      The U−Ti−Zr system was assessed by means of the CALPHAD method for the first time. Based on a critical evaluation of experimental phase diagram data available in the literature, a thermodynamic modeling was conducted for the individual phases. The solution phases including the liquid, hcp and bcc were described by a substitutional solution model. The binary compounds, U2Ti and UZr2, with a ternary extension were treated as one single phase using a sublattice model of (U,Zr)2/3(Ti,Zr)1/3. There is no ternary compound in this system. A set of self-consistent thermodynamic parameters for the U−Ti−Zr system was then obtained. Comparisons between the calculated and measured phase diagrams show that the experimental information is satisfactorily accounted for by the present thermodynamic description. The solvus projection and reaction scheme were generated using the present thermodynamic parameters. The presently calculated phase diagrams of U–Zr−Ti alloys can be used for further industrial application.

      PubDate: 2017-12-27T12:27:34Z
       
  • Interdiffusion and atomic mobility in bcc Ti–rich
           Ti–Nb–Zr system
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): Weimin Chen
      Accurate interdiffusion information is the necessity for the control of the production of homogeneous biomedical alloys. Ternary interdiffusivities in bcc Ti–rich Ti–Nb–Zr alloys at 1273K were determined by using the combination of the diffusion couple technique and the Matano–Kirkaldy method. Subsequently, on the basis of the presently obtained interdiffusivities together with the diffusivity and mobility parameters of sub–binary Ti–Nb–Zr system and the thermodynamic descriptions for bcc Ti–Nb–Zr system, the atomic mobilities of Ti, Nb and Zr in bcc Ti–Nb–Zr alloys were assessed by means of DICTRA (DIffusion Controlled TRAnsformation) software package. Moreover, the comprehensive comparisons between the experimental diffusion properties (i.e., interdiffusivities, composition profiles, interdiffusion fluxes and diffusion paths) and the calculated/model–predicted data due to the present atomic mobilities were conducted in order to verify the reliability of the mobilities. The present atomic mobilities for bcc Ti–Nb–Zr system can provide the accurate interdiffusivity matrix over the wide composition range.

      PubDate: 2017-12-27T12:27:34Z
       
  • Composition-dependent interdiffusivity matrices in face centered cubic
           Ni–Al–X (X = Rh and W) alloys at 1423, 1473 and 1523K: A
           high-throughput experimental measurement
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): Juan Chen, Lijun Zhang
      Based on 18 face centered cubic (fcc) single-phase diffusion couples in ternary Ni–Al–X (X = Rh and W) systems together with the recently developed numerical inverse method, high-throughput measurements of the composition-dependent interdiffusivity matrices in fcc Ni–Al–X (X = Rh and W) alloys at 1423, 1473 and 1523K were performed in the present work. Their reliability was comprehensively validated through comparison between the model-predicted composition/interdiffusion flux profiles for each diffusion couple and the corresponding experimental data. Moreover, the direct comparison with the interdiffusivities evaluated from traditional Matano-Kirkaldy method as well as those from the literature and in the boundary binary systems was also made. The errors for the determined interdiffusivities were evaluated by a scientific method considering the error propagation. The three-dimensional main interdiffusivity planes for fcc Ni–Al–X (X = Rh and W) systems over the investigated concentration ranges at 1423, 1473 and 1523K were subsequently constructed. It was then found that D ˜ A l A l N i is generally larger than D ˜ R h R h N i , while D ˜ W W N i is the smallest.

      PubDate: 2017-12-27T12:27:34Z
       
  • Phase equilibria studies of CaO-SiO2-Al2O3-Fe2O3-MgO system using CALPHAD
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): Tazuddin, Hemantkumar N. Aiyer, Amit Chatterjee
      A detailed CALPHAD (CALculation of PHAse Diagram) based thermodynamic study on CaO- SiO2-Al2O3-Fe2O3-MgO system (C-A-S-F-M) has been carried out to study the evolution of phases during heating and to investigate the effects of individual oxides. The important phases present at high temperature in the system are tricalcium silicate (C3S), dicalcium silicate (C2S), tricalcium aluminate (C3A), dicalcium ferrite (C2F) and a liquid phase. The evolution of liquid phase and other important phases predicted by CALPHAD closely matches with the experimental results. It was observed that in C-A-S-F-M system, there is a critical percentage of CaO and SiO2 at which C3S is maximum. Both Fe2O3 and Al2O3 significantly increase the amount of liquid phase. Both Fe2O3 and Al2O3 reduce C3S and increase C2S in the system. Up to 1.5wt%, MgO also helps in increasing liquid phase. A mathematical model to predict phases has been developed as an alternative to the Bougue's equation which is very effective in predicting phase fractions.

      PubDate: 2017-12-27T12:27:34Z
       
  • Thermodynamic assessment of binary erythritol-xylitol phase diagram for
           phase change materials design
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): Saman Nimali Gunasekara, Huahai Mao, Sedigheh Bigdeli, Justin NingWei Chiu, Viktoria Martin
      Here, the erythritol-xylitol binary system was thermodynamically optimized based on available experimental phase equilibrium data, to explore compositions suitable as phase change materials (PCMs) for thermal energy storage (TES). A previous experimental study revealed that erythritol-xylitol was a partially isomorphous system with a eutectic. In the thermodynamic evaluation, the CALPHAD method was employed coupling the phase diagram and thermodynamic property information. There, both unary and binary systems’ experimental data were taken into account, and all phases were described using the substitutional solution model. Finally, a self-consistent thermodynamic description for the erythritol-xylitol system was achieved. The calculated eutectic point is at 76.7°C and 26.8mol% erythritol, agreeing well with the experimental data. The calculated phase diagram better-verifies the systems’ solidus and the solvus, disclosing the stable phase relations. Based on the Gibbs energy minimization, phase diagrams can be predicted for the binary and higher order systems, provided the component subsystems are thermodynamically assessed beforehand. In conclusion, to move forward beyond e.g. non-isomorphous simple eutectic systems, methods using Gibbs free energy minimization from a fundamental point-of-view such as CALPHAD are essential.

      PubDate: 2017-12-13T09:33:36Z
       
  • Thermodynamics of liquid Sn-Pb alloys determined by vapour pressure
           measurements
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): Andrzej Zajączkowski
      Application of Knudsen method in the studies of liquid Sn-Pb alloys, containing from 4.85 to 95.31mol% of lead, in temperatures from 851 to 1186K, and liquid tin and lead, in temperatures 1360 – 1442 and 934 – 1149K, respectively, provided experimental data which made characterization of thermodynamic properties of liquid phase of Sn-Pb system possible. Parameters of the Redlich-Kister equation, describing excess Gibbs energy of liquid phase of the examined system, were determined. With application of the third law method standard enthalpies of sublimation of tin and lead were calculated.

      PubDate: 2017-12-13T09:33:36Z
       
  • Assessment of the Al-Bi-Mg system and extrapolation to the Al-Bi-Mg-Sn
           quaternary system
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): Chunju Niu, Changrong Li
      The phase equilibria in the Al-Bi-Mg-Sn quaternary system have been studied using the CALPHAD (CALculation of PHAse Diagram) method. One of the four ternary systems constituting the quarternary system, the Al-Bi-Mg system, is re-assessed by means of the CALPHAD technique and Thermo-Calc software package, in consideration of the associate model for the liquid phase instead of the Modified Quasi-chemical Model used in the literature report. While for the other three ternary systems, the Al-Bi-Sn, the Al-Mg-Sn and the Bi-Mg-Sn systems, the thermodynamic parameters are mainly adopted from the literature reported optimization results with a little modification to the Al-Bi-Sn and the Al-Mg-Sn systems for the compatibility of all the constituent binary systems. The assessment results of the Al-Bi-Mg ternary system are in good agreement with the available experimental phase relations, including the liquidus surface projection and the vertical sections. The thermodynamic database of the Al-Bi-Mg-Sn quaternary system was developed without the consideration of the quaternary interactions and the quaternary compounds. With this newly developed thermodynamic database, the phase equilibria and the solidification processes of the ternary and the quarternary systems are calculated and analyzed.

      PubDate: 2017-12-13T09:33:36Z
       
  • Experimental investigation and simulation of precipitation evolution in
           Mg-3Nd-0.2Zn alloy
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): Xiangyu Xia, Amirreza Sanaty-Zadeh, Chuan Zhang, Alan A. Luo, Donald S. Stone
      In this research, precipitation evolution and strengthening behavior in Mg-3Nd-0.2Zn alloy during isothermal age treatment at 200°C are quantitatively studied by a combination of experimental investigation and computational simulation. Microstructure evolution, including volume fraction, number density, and size of precipitates are first measured by TEM and DSC techniques and then modeled using an integrated computational simulation method combining the CALPHAD (CALculation of PHAse Diagram) approach and classical nucleation model. The focus of the analysis is set on the evolution of key strengthening precipitate β’. Critical kinetic parameters such as particle interfacial energy and nucleation site number are obtained computationally by fitting the model to the experimental data. Mechanical properties of a series of Mg-Nd-Zn alloys are predicted using the simulated microstructure evolution as inputs. Good agreement is found between simulated and measured results. Strategies for enhancing the precipitation hardening effect are presented and discussed based on the simulation results. The merit of this study is to use the obtained parameters to extrapolate microstructure evolution and mechanical properties when adjusting alloy composition and/or heat treatment conditions within a certain range, which will be very useful for further development and optimization of multi-component Mg alloys.

      PubDate: 2017-12-13T09:33:36Z
       
  • Genetic programming based models for prediction of vapor-liquid
           equilibrium
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): Veena Patil-Shinde, Sanjeev S. Tambe
      The design, operation, and control of chemical separation processes heavily rely on the knowledge of the vapor-liquid equilibrium (VLE). Often, conducting experiments to gain an insight into the separation behavior becomes tedious and expensive. Thus, standard thermodynamic models are used in the VLE prediction. Sometimes, exclusively data-driven models are also used in VLE prediction although this method too possesses drawbacks such as a trial and error approach in specifying the data-fitting function. For overcoming these difficulties, this paper employs a machine learning (ML) formalism namely “genetic programming (GP)” possessing certain attractive features for the VLE prediction. Specifically, three case studies have been performed wherein GP-based models have been developed using experimental data, for predicting the vapor phase composition of a ternary, and a group of non–ideal binary systems. The inputs to models consists of three pure component attributes (acentric factor, critical temperature, and critical pressure), and as many intensive thermodynamic parameters (liquid phase composition, pressure, and temperature). A comparison of the VLE prediction and generalization performance of the GP-based models with the corresponding standard thermodynamic models reveals that the former class of models possess either superior or closely comparable performance vis-a-vis thermodynamic models. Noteworthy features of this study are: (i) a single GP-based model can predict VLE of a group of binary systems, and (ii) applicability of a GP-based model trained on an alcohol-acetate series data for its higher homolog. The VLE modeling approach exemplified here can be gainfully extended to other ternary and non-ideal binary systems, and for designing corresponding experiments in different pressure and temperature ranges.

      PubDate: 2017-12-13T09:33:36Z
       
  • Experimental reinvestigation and thermodynamic description of Bi-Te binary
           system
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): Cun Mao, Mingyue Tan, Ligang Zhang, Di Wu, Weiming Bai, Libin Liu
      The Bi-Te phase diagram was determined by equilibrium alloy method, combined with electron probe microanalysis (EPMA), X-ray diffraction (XRD) and thermal analysis (DSC). The experimental result shows that there is a β-phase with a large composition range at low temperature, while Bi2Te and Bi4Te3 are relatively stable in the solid-liquid region. A consistent phase diagram that covers the experimental findings has been achieved. Based on the new experimental phase diagram, coupling with the reported thermodynamic data, the thermodynamic optimization of the Bi-Te binary system was carried out with the help of CALPHAD approach. A group of reasonable thermodynamic parameters was obtained.

      PubDate: 2017-12-13T09:33:36Z
       
  • Reconciling SGTE and ab initio enthalpies of the elements
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): Axel van de Walle
      The CALPHAD framework is built on assumption that all phases have a well-defined free energy over all accessible composition, temperature and pressure conditions. Unfortunately, it is common for phases to exhibit mechanical instabilities in at least some range of conditions, thus precluding direct experimental measurements and hindering computational efforts. A pragmatic solution has often been to extrapolate free energies from stable region into the unstable regions, but extrapolations from different systems that share a common phase may not agree and extrapolated free energies can unintentionally lie below the free energy of stable phases. Computational approaches that aim to directly calculate the free energy of unstable phases offer a promising avenue to address these issues. Among them, the recently proposed “inflection detection” scheme lies on a strong theoretical footing. We provide further support for this approach by demonstrating that it yield free energies that agree very well with the widely used SGTE (Scientific Group Thermodata Europe) data for pure elements. This finding suggest that it may be possible to get the best of both worlds: obtain a theoretically justified definition of the free energy of mechanically unstable phases and preserve much of existing empirical standards for the assignments of such free energies.
      Graphical abstract image Highlights fx1

      PubDate: 2017-11-16T10:46:39Z
       
  • Density functional study of the thermodynamic properties and phase diagram
           of the magnesium hydride
    • Abstract: Publication date: March 2018
      Source:Calphad, Volume 60
      Author(s): Hasan S. AlMatrouk, Viorel Chihaia, Valentin Alexiev
      This paper focuses primarily on the P-T phase diagram determination by considering six polymorphs of magnesium hydride (α - rutile TiO2, P4 2 /mnm, β - cubic modified CaF2, Pa 3 ¯ , γ - orthorhombic PbO2, Pbcn, δ' - orthorhombic, Pbca and cubic - Fm 3 ¯ m). The Gibbs free energy and other thermodynamic properties were evaluated by DFT-based thermodynamic calculations, within the frame of the quasi-harmonic approximation, for the pressure range 0–10GPa and temperatures between 0 and 1200K. Furthermore, the structural, energetic, and electronic properties of the investigated structures are conversed.

      PubDate: 2017-11-16T10:46:39Z
       
  • Thermodynamic modeling of the V-Si-B system
    • Abstract: Publication date: December 2017
      Source:Calphad, Volume 59
      Author(s): Antonio Augusto Araujo Pinto da Silva, Nabil Chaia, Flavio Ferreira, Gilberto Carvalho Coelho, Jean-Marc Fiorani, Nicolas David, Michel Vilasi, Carlos Angelo Nunes
      In the present work, the V-Si-B ternary system was thermodynamically modeled using the CALPHAD method. The thermodynamic descriptions of the V-Si and B-Si binary systems were taken from literature while the parameters of binary V-B were re-evaluated, based on new experimental information. The ternary thermodynamic description was based on experimental data of isothermal section and liquidus projection. The binary compounds V3B2, VB, V5B6, V3B4, V2B3 and VB2 were modeled as stoichiometric phases; the terminal solid solutions BCC and β-Rhomb were modeled using the sublattice models (V,Si)1(B,va)3 and (B)93(B, Si)12; the ternary phases D88 and T2 were modeled as (V)0.5556(B,Si)0.3333(B,va)0.1111 and (V)0.625(B,Si)0.375, respectively. A set of thermodynamic parameters is proposed and the results showed a good agreement with available experimental information from the literature.

      PubDate: 2017-11-09T09:20:00Z
       
  • First-principles calculations and thermodynamic modeling of the Yb-Ni
           binary system
    • Abstract: Publication date: December 2017
      Source:Calphad, Volume 59
      Author(s): Yong-Jie Hu, Yi Wang, Samad A. Firdosy, Kurt E. Star, Jean-Pierre Fleurial, Vilupanur A. Ravi, Zi-Kui Liu
      A complete thermodynamic description of the Yb-Ni binary system is developed by means of the CALculation of PHAse Diagram (CALPHAD) method in combination with first-principles calculations based on density functional theory (DFT) and available experimental data in the literature. Finite temperature thermodynamic properties of the Yb-Ni intermetallic compounds are predicted using the quasi-harmonic approach, where first-principles phonon calculations are performed to calculate the lattice vibrational entropy. The associate solution model is used to describe the complex thermodynamic behavior of the liquid phase. The calculated phase diagram agrees well the experimental phase equilibrium data in the literature. By the coupling of CALPHAD modeling with first-principles calculations, the present work provides a more thermodynamically accurate model of the Yb-Ni system when compared to previous models.

      PubDate: 2017-11-09T09:20:00Z
       
  • Thermodynamic re-assessment of the Fe-Dy and Fe-Tb binary systems
    • Abstract: Publication date: December 2017
      Source:Calphad, Volume 59
      Author(s): M.H. Rong, X.L. Chen, J. Wang, G.H. Rao, H.Y. Zhou
      In this work, based on the critical evaluation of previous optimizations and available experimental data in the published literature, the Fe-Dy and Fe-Tb binary systems were re-assessed thermodynamically using the CALPHAD method. The solution phases including liquid, fcc-Fe, bcc-Fe, bcc-Dy, bcc-Tb, hcp-Dy and hcp-Tb, were described by the substitutional solution model and their excess Gibbs energies were expressed with the Redlich-Kister polynomial. Due to their narrow homogeneity ranges, the intermetallic compounds, Fe17Dy2, Fe23Dy6, Fe3Dy, Fe2Dy, Fe17Tb2, Fe23Tb6, Fe3Tb and Fe2Tb, were modeled as stoichiometric compounds. Self-consistent thermodynamic parameters to describe the Gibbs energies of various phases in the Fe-Dy and Fe-Tb binary systems were obtained finally. The calculated results are in good agreement with the reported phase equilibria and thermodynamic properties.

      PubDate: 2017-11-02T09:09:19Z
       
  • Numerical modelling of moving interfaces under local equilibrium
           conditions
    • Abstract: Publication date: December 2017
      Source:Calphad, Volume 59
      Author(s): Jae Sang Lee, Dong-Woo Suh, Yang Mo Koo, Seong Gyoon Kim
      A new method is presented to simulate moving interfaces during diffusion-controlled growth under local equilibrium conditions. The position and compositions of the interface are obtained directly from the equilibrium state of the subsystem around the moving interface, without iterative calculation between diffusion fluxes and solute balance conditions. The method is applicable to general multi-component systems, and it ensures the consistency in compositions and solute balance at the interfaces; Those are ascribed to the presented consideration of subsystem around the interface region in a discretized form. Explicit equations of interface compositions and position in discretized variables are also presented for the simplified ternary systems of two-solution and compound/solution. The validity and usefulness of the method is demonstrated by simulations of the two important ternary systems; The simulation results illustrate the features of diffusion-controlled growth with different alloy compositions and diffusivities of solutes in both systems.
      Graphical abstract image

      PubDate: 2017-11-02T09:09:19Z
       
  • Thermodynamic modeling of phase equilibria and defect chemistry in the
           Zn-S system
    • Abstract: Publication date: December 2017
      Source:Calphad, Volume 59
      Author(s): Pin-Wen Guan, Shun-Li Shang, Greta Lindwall, Tim Anderson, Zi-Kui Liu
      Though important and fundamental, a satisfactory theoretical framework of modeling multiple point defects in the context of phase equilibria is still lacking. In this work, a methodology that models point defects, electrons, holes and the underlying phase equilibria simultaneously is developed and applied to the Zn-S system. It overcomes some issues in previous works, such as inconsistency in the reference state for electrons. The model parameters are directly related to the Gibbs energy of formation of point defects computed from first-principles phonon calculations. A double exponential function is proposed to parameterize the entropy of formation of point defects as a function of temperature. Using this approach, phase diagrams, concentrations of point defects and free carriers, the majority carrier, and defect-related properties exemplified by the electrical conductivity are obtained under various conditions, in agreement with experimental data. The present methodology provides a way to integrate first-principles calculations and experimental data into the CALPHAD model, enabling description of multi-component semiconductor systems.

      PubDate: 2017-11-02T09:09:19Z
       
  • Phase relations in the Cu-O-Al2O3-SiO2 system at 1150°C and
           1300°C in air
    • Abstract: Publication date: December 2017
      Source:Calphad, Volume 59
      Author(s): Niko Hellstén, Pekka Taskinen
      Phase equilibria of the Cu-O-Al2O3-SiO2 system are important in the processing of copper aluminosilicate glasses, mullite ceramics and in non-ferrous metallurgy. We experimentally investigated the phase equilibria of this system at 1150°C and 1300°C in air atmosphere using equilibration and quenching method. Chemical compositions of the liquid and solid phases in the quenched samples were determined by Electron Probe Microanalysis (EPMA). Based on the results, we constructed an isothermal section containing the liquidus contours of various primary phases at 1300°C. Comparison of these results with previous experimental work confirms that oxygen pressure affects phase stability and composition of the liquidus in this system. The experimental liquidus determined in this work disagrees by up to 50wt% with the calculated values of MTDATA 6.0 software and Mtox database version 8.2. Concentration of ‘Cu2O′ in mullite ranged from 0.46wt% to 1.25wt%. The results of this work will enable improvement of thermodynamic descriptions for this system.

      PubDate: 2017-11-02T09:09:19Z
       
  • Experimental investigation and thermodynamic calculation of the B-Fe-Mo
           ternary system
    • Abstract: Publication date: December 2017
      Source:Calphad, Volume 59
      Author(s): Xuemei Ou Yang, Fucheng Yin, Jingxian Hu, Manxiu Zhao, Ye Liu
      The phase relationship of the B-Fe-Mo ternary system has been investigated combining experimental results with thermodynamic modeling. The liquidus projection of the ternary system in the Fe-rich region was constructed by identifying primary crystallization phases in the as-cast alloys and determining liquid temperatures obtained from the DSC analyses. Eight different primary solidification regions were observed, and they are BCC, FCC, Mo2FeB2, Fe2B, FeB, σ, and R, respectively. And four invariant reactions were identified in the Fe-rich region. Thermodynamic optimization of the B-Fe-Mo ternary system was performed using CALPHAD approach based on the thermodynamic models of the three constitutional binary systems and the experimental results of the ternary system. A set of self-consistent thermodynamic parameters for the B-Fe-Mo system were obtained with reasonable agreement between the experimental and calculated results.

      PubDate: 2017-11-02T09:09:19Z
       
  • CALPHAD modeling of metastable phases and ternary compounds in Ti-Al-N
           system
    • Abstract: Publication date: December 2017
      Source:Calphad, Volume 59
      Author(s): Yanhui Zhang, Peter Franke, Hans Jürgen Seifert
      The development and evaluation of thermodynamic databases for the Ti-Al-N system is important for a wide range of engineering alloys. In this work, we resorted to the integration of ab initio thermodynamics, experiments and CALPHAD modeling for a comprehensive understanding of the metastable and the ternary phases in Ti-Al-N system. The supersaturated solutions of (Ti,Al)N with both rocksalt and wurtzite structures were well described by using the sub-regular solution model. Thereby, the formation, the phase separation and the meta-solubility of TiAlN coatings were successfully elaborated by the metastable pseudo-binary TiN-AlN section and the PVD (physical vapor deposition) phase diagram. Moreover, a number of isothermal and isopleth sections were also calculated and compared with available experiments and previous thermodynamic assessments. For the first time the ternary compound of τ 3 was corrected as Ti 4 AlN 3 in our proposed database.

      PubDate: 2017-10-14T14:28:02Z
       
  • Thermodynamic re-assessment of the Al-Co-W system
    • Abstract: Publication date: December 2017
      Source:Calphad, Volume 59
      Author(s): Peisheng Wang, Wei Xiong, Ursula R. Kattner, Carelyn E. Campbell, Eric A. Lass, Oleg Y. Kontsevoi, Gregory B. Olson
      The Al-Co-W system and its binary sub-systems Al-Co, Al-W and Co-W were critically reviewed. The thermodynamic description of the Al-Co-W system including all three binaries was developed considering thermodynamic and constitutional data of the systems. Results from density functional theory calculations were employed to improve reliability of the descriptions. The Gibbs energy for the thermal vacancy (GVa) in the BCC_A2 phase is discussed. The revised descriptions obtained for the Al-W and Co-W systems describe the thermodynamic and phase equilibrium data well and are free of undesired artefacts for temperatures below 6000K. The ordered γ’ phase of the Al-Co-W system is described as a metastable phase in the entire temperature range. The calculated Gibbs energy of the γ’ is only slightly above that of the equilibrium state, which indicates that there is good possibility of stabilizing the γ’ phase with the addition of γ’-stabilizing elements, such as Ti, Ta, Hf, Nb and Ni.

      PubDate: 2017-10-11T14:13:11Z
       
  • Second nearest-neighbor modified embedded-atom method interatomic
           potentials for the Pt-M (M = Al, Co, Cu, Mo, Ni, Ti, V) binary systems
    • Abstract: Publication date: December 2017
      Source:Calphad, Volume 59
      Author(s): Jin-Soo Kim, Donghyuk Seol, Joonho Ji, Hyo-Sun Jang, Yongmin Kim, Byeong-Joo Lee
      Interatomic potentials for Pt-M (M = Al, Co, Cu, Mo, Ni, Ti, V) binary systems have been developed on the basis of the second nearest-neighbor modified embedded-atom method (2NN MEAM) formalism. The parameters of pure Mo have also been newly developed to solve a problem in the previous 2NN MEAM potential in which the sigma and α-Mn structures become more stable than the bcc structure. The potentials reproduce various materials properties of alloys (structural, thermodynamic and order-disorder transition temperature) in reasonable agreements with relevant experimental data and other calculations. The applicability of the developed potentials to atomistic investigations for the shape and atomic configuration of Pt bimetallic nanoparticles is demonstrated.

      PubDate: 2017-10-11T14:13:11Z
       
  • A new thermodynamic description of stable Cr-carbides for the third
           generation of thermodynamic database
    • Abstract: Publication date: December 2017
      Source:Calphad, Volume 59
      Author(s): Zhou Li, Huahai Mao, Malin Selleby
      An updated thermodynamic description of the stable Cr-carbides was obtained by applying the same models as used for the elements within the 3rd generation of thermodynamic databases. The Einstein model was used and a scaling factor was introduced to take into account the coupling effect between the stoichiometry (C to Cr ratio) and the structure of the compound. Using this model we could accurately describe the thermodynamic properties of these stoichiometric compounds using available experimental heat capacity data. The new description is now more physically sound and results in a better agreement with the experimental heat capacity data.

      PubDate: 2017-10-03T13:00:11Z
       
  • Thermodynamic modeling of the Ta–Mo–C ternary system
    • Abstract: Publication date: December 2017
      Source:Calphad, Volume 59
      Author(s): Cong Zhang, Haiqing Yin, Yong Du, Yafei Pan, Peng Deng
      The Ta–Mo–C system was assessed by means of the CALPHAD approach. All of the phase diagram and thermodynamic information available from the literature were critically reviewed. The liquid was modeled as substitutional solution phase, while the carbides including fcc-(Mo,Ta)C1-x , bcc-(Mo,Ta), hcp-(Mo,Ta)2C and η-MoC were described by using corresponding sublattice models. The ζ-Ta4C3-x was considered as a linear compound with carbon content fixed, while shp-MoC was treated to be a binary stoichiometric phase. There was no ternary compound reported in this system. The modeling of Ta–Mo–C ternary system covers the entire composition and temperature ranges, and a set of self-consistent thermodynamic parameters for the Ta–Mo–C system was systematically optimized. Comprehensive comparisons between the calculated and reported phase diagram and thermodynamic data show that the reliable information is satisfactorily accounted for by the present modeling. The liquidus projection and reaction scheme of the Ta–Mo–C system were also generated by using the present thermodynamic parameters.

      PubDate: 2017-09-26T12:20:07Z
       
  • Thermodynamic modeling of the Ca(NO3)2-MNO3 (M: alkali metal) systems
    • Abstract: Publication date: December 2017
      Source:Calphad, Volume 59
      Author(s): Xiang Li, Kun Wang, Miao Shen, Zhu Wu, Leidong Xie
      This work presents a thermodynamic evaluation of the Ca(NO3)2-MNO3 (M: Li, Na, K, Rb, Cs) binary systems using the CALPHAD approach. The required Gibbs energy of liquid Ca(NO3)2 is missing in the literature and has been successfully evaluated in the present work with a fusion enthalpy of 23849Jmol−1. The substitutional solution model can thus be employed to describe the Ca(NO3)2-base liquid phase. All the intermediate compounds are treated to be stoichiometric and their Gibbs energies comply with the Neumann-Kopp rule. Empirical functions relating mixing enthalpies to ionic parameters are employed to predict the corresponding values of binary melts which are used as input data to assist in parameters optimization for the liquid phases. The final calculated results show good agreement with most of the experimental and predicted data.

      PubDate: 2017-09-19T14:40:54Z
       
  • Diffusivities and atomic mobilities for fcc Cu–Ni–Sn alloys
    • Abstract: Publication date: December 2017
      Source:Calphad, Volume 59
      Author(s): Yuling Liu, Chong Chen, Dandan Liu, Yong Du, Shuhong Liu, Xiaoma Tao, Yifang Ouyang
      Utilizing five groups of bulk diffusion couples together with electron probe microanalysis technique, the composition-dependent ternary interdiffusion coefficients in fcc Cu–Ni–Sn alloys at 1023K were determined via the Whittle and Green method. The presently obtained interdiffusion coefficients at 1023K as well as our previously measured ones at 1073K were combined with the slightly modified thermodynamic descriptions of the fcc Cu–Ni–Sn phase to explore atomic mobilities of Cu, Ni and Sn in fcc Cu–Ni–Sn alloys within the CALPHAD framework. In order to be consistent with the thermodynamic description, atomic mobilities in binary fcc Ni–Sn alloys were re-evaluated in the present work. The quality of the assessed kinetic characteristics was confirmed by the comprehensive comparisons between various model-predicted diffusion behaviors and the experimental ones, including concentration profiles and diffusion paths.

      PubDate: 2017-09-14T08:18:29Z
       
  • Ab initio-assisted assessment of the CaO-SiO2 system under pressure
    • Abstract: Publication date: December 2017
      Source:Calphad, Volume 59
      Author(s): D. Belmonte, G. Ottonello, M. Vetuschi Zuccolini
      We present the results of an ab initio-assisted assessment of melting and subsolidus phase relations in the system CaO-SiO2 up to high pressure conditions. All solid compounds known to nucleate in the system have been treated as purely stoichiometric and the liquid resolved in the framework of a simple polymeric model. Mixing properties of the binary liquid phase are fully described by a single-parameter purely enthalpic chemical interaction plus a strain energy contribution. The latter is required to predict liquid immiscibility of SiO2-rich liquid compositions at ambient conditions and becomes irrelevant at P>2GPa. A detailed survey of thermodynamic properties of silica polymorphs and calcium oxide and silicates in a broad range of P-T conditions reveals quite controversial stability relations and melting behavior. First-principles calculations on CaO and SiO2 pure liquid components and solid phases (lime and stishovite) have been used, along with a sound assessment of first- and second-order phase transitions, to reconcile thermochemical data with topological details of the observed phase diagrams. A physically-consistent coupling between thermodynamic and thermoelastic properties (viz. compressibility and thermal expansion) turns out to be of fundamental importance to infer reliable stability relations both at subsolidus and melting conditions. Pressure effects shift the composition of the main invariant points in the CaO-SiO2 system and also change the melting behavior of the CaSiO3 metasilicate in a complex manner.

      PubDate: 2017-09-02T07:41:30Z
       
  • Phase equilibria in the ternary Fe-Co-S system
    • Abstract: Publication date: December 2017
      Source:Calphad, Volume 59
      Author(s): Mariia O. Ilatovskaia, Svetlana I. Sinyova, Roman V. Starykh
      The Fe-FeS-CoS-Co system has been investigated experimentally from 1073K up to liquidus temperature. Samples of the system have been investigated using DTA/TGA, SEM/EDX, and XRD methods. Liquidus and solidus projections have been plotted based on experimental data.

      PubDate: 2017-09-02T07:41:30Z
       
  • Vapor pressure of alkali-metal binary alloys in glass cells
    • Abstract: Publication date: December 2017
      Source:Calphad, Volume 59
      Author(s): Kiyoshi Ishikawa
      The alkali partial pressures of composite alkali-metal vapor are crucial in atomic-physics optical experiments. The vapor pressures of alkali-metal binary alloys can be calculated by using the activity and the mixing enthalpy for homogeneous alloys from early measurements. We show that the results of sodium-containing alloys deviate appreciably from the prediction of Raoult's law. Experimentally, the phase and the mixing ratio of binary alloys are non-destructively measured by nuclear-magnetic-resonance spectroscopy in glass cells. We find that many droplets of the sodium-rubidium alloy exist on the cell walls, and they have different mixing ratios. Therefore, the vapor density varies microscopically around the glass cells. To achieve precision optical measurements, we should take account of the pressure change due to the equilibrium process and further sodium contamination over the lifetime of glass cells.

      PubDate: 2017-09-02T07:41:30Z
       
  • The reassessment of the Al-V system and new assessment of the Al-Si-V
           system
    • Abstract: Publication date: December 2017
      Source:Calphad, Volume 59
      Author(s): A. Kroupa, M. Mazalová, K.W. Richter
      The theoretical assessment of the Al-Si-V system has been carried out and has been presented here. The experimental results from Huber et al. [1,2] were used as the basis of the assessment. The relevant binary system assessments for Al-V [9], Al-Si [13] and Si-V [14] were used in the initial stage of the study and it was found that complete reassessment of the Al-V system was necessary. The reassessed dataset for the Al-V system is in very good agreement not only with existing experimental phase diagram and thermodynamic data, but is also consistent with the independent work of Lindahl et al. [22]. The final assessment of the Al-Si-V system using our own reassessed Al-V system is in excellent agreement with the experimental data.

      PubDate: 2017-09-02T07:41:30Z
       
  • Thermodynamic reassessment of the novel solid-state thermal energy storage
           materials: Ternary polyalcohol and amine system
           pentaglycerine-tris(hydroxymethyl)-amino-methane-neopentylglycol
           (PG-TRIS-NPG)
    • Abstract: Publication date: December 2017
      Source:Calphad, Volume 59
      Author(s): Renhai Shi, Dhanesh Chandra, Amrita Mishra, Anjali Talekar, Muralidhar Tirumala, Daryl J. Nelson
      Organic polyalcohol and amine globular molecular crystals such as PG, TRIS, and NPG are considered as the most promising potential candidates for solid-state thermal energy storage in the orientationally disordered high temperature phases. In this study, we first propose a new PG-TRIS-NPG phase diagram based on experimental data of the three sub-binary systems NPG-PG, PG-TRIS, and NPG-TRIS with CALPHAD methodology. The NPG-PG binary phase diagram was optimized using sub-regular models that showed complete miscibility in the entire compositional range of high temperature γ′ (FCC) phase region, and an invariant equilibrium point at 299.5K. The NPG-TRIS binary system was also calculated using sub-regular model, from sub-ambient to well above the melting temperatures, and determined three invariant equilibria at 311.1K, 391.8K, and 410.6K, respectively. These calculated binary phase diagrams are in good agreement with the experimental data. The PG-TRIS-NPG ternary system has also been calculated and qualitatively analyzed using the CALPHAD method and Thermo-Calc software. A set of self-consistent thermodynamic parameters formulating the Gibbs energies of various phase in the PG-TIRS-NPG ternary system are obtained in the present work. Thermodynamic properties such as several isotherms, isopleths, and liquidus projections are calculated by using present datasets as shown in this work in which the solid ternary compound (TRIS0.5NPG0.5)XPG1−X (0.1≤x≤0.9), (TRIS0.5PG0.5)XNPG1−X (0.1≤x≤0.9), and (PG0.5NPG0.5)XTRIS1−X (0.1≤x≤0.9) with various solid-solid phase transitions at different temperatures could apply to applications in the solid-state thermal energy storage.

      PubDate: 2017-09-02T07:41:30Z
       
  • A method of integrating CALPHAD data into phase-field models using an
           approximated minimiser applied to intermetallic layer growth in the Al-Mg
           system
    • Abstract: Publication date: December 2017
      Source:Calphad, Volume 59
      Author(s): M.J. Welland, M.H.A. Piro, S. Hibbins, N. Wang
      This article describes an approach to combine single phase thermodynamic potentials into a multiphase composite potential suitable for integration in a multicomponent phase-field model. The composite potential avoids implicit interfacial energy contributions by starting from a grand potential formulation. The method is made explicit by expanding the minimiser resulting from the Legendre transform between grand and Helmholtz potentials about a known equilibrium state. The resulting composite function is explicit, reproduces the equilibrium states exactly, and is smooth such that it can be differentiated to provide the driving forces for mass transport and phase change in a thermodynamically self-consistent manner. The model is demonstrated by simulating a sequence of phase transformations for intermetallic growth in Al-Mg interdiffusion for advanced nuclear research reactor fuel.

      PubDate: 2017-09-02T07:41:30Z
       
  • Experimental investigation and thermodynamic description of the Cu-Cr-Zr
           system
    • Abstract: Publication date: December 2017
      Source:Calphad, Volume 59
      Author(s): Yuling Liu, Peng Zhou, Shuhong Liu, Yong Du
      The Cu-Cr-Zr ternary system was investigated via thermodynamic modeling coupled with key experiments. The isothermal section of the Cu-Cr-Zr system at 1123K was determined by means of optical microscopy, X-ray diffraction and electron probe microanalysis, and the phase transformation temperatures were measured by differential scanning calorimetry. The Cu-Cr sub-binary system was re-assessed with a substitutional solution model for the solution phases to ensure its compatibility in multi-component system. A set of self-consistent thermodynamic parameters for the Cu-Cr-Zr systems was obtained using the CALPHAD (CALculation of PHAse Diagram) approach, and the calculated phase diagram is in a satisfactory agreement with the present experimental results and literature information. An increase of the thermodynamic stability for the CuZr and Cr2Zr phases due to the ternary solubility is verified by calculation.

      PubDate: 2017-08-03T11:16:57Z
       
  • Experimental and thermodynamic study of the Mg-Sn-Ca-Sr quaternary system:
           Part I-Mg-Sn-Ca ternary system
    • Abstract: Publication date: September 2017
      Source:Calphad, Volume 58
      Author(s): Jian Wang, Jiajian Han, Beining Du, Yixiong Huang, Liyuan Sheng, Weifeng Rao, Cuiping Wang, Xingjun Liu
      Four key samples of the Mg-Ca-Sn ternary system in the Mg-rich region at 415 and 350°C have been determined using the Scanning Electron Microscopy (SEM) equipped with Energy Dispersive X-Ray Spectrometry (EDS). The existence of the CaMgSn ternary compound was confirmed in these two isothermal sections. Thermodynamic optimizations of the Ca-Sn binary system and Mg-Ca-Sn ternary system were carried out using the CALPHAD (Calculation of Phase Diagrams) technique. The Modified Quasichemical Model (MQM) was used for the liquid solution which exhibits a high degree of short-range ordering behavior in the liquid solution. The solid phases are modeled with the Compound Energy Formalism (CEF). Finally, a self-consistent thermodynamic database of Mg-Ca-Sn ternary system has been constructed in the present work, which would provide an efficient and convenient way to study and develop the new Mg-Sn based alloys.

      PubDate: 2017-05-13T11:33:23Z
       
  • Thermodynamic model for prediction of binary alloy nanoparticle phase
           diagram including size dependent surface tension effect
    • Abstract: Publication date: September 2017
      Source:Calphad, Volume 58
      Author(s): Fatemeh Monji, Mohammad Amin Jabbareh
      Considering the size effect of nanoparticles on surface tension, a new CALPHAD type thermodynamic model was developed to predict phase diagram of binary alloy nanoparticle systems. In contrast to conventional model, the new model can be applied to the nanoparticles smaller than the critical size (5NM in radius). For an example, the model applied to Ag – Au binary system and the results were compared with experimental data as well as conventional CALPHAD model and molecular dynamics simulation results.

      PubDate: 2017-05-02T10:41:32Z
       
 
 
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