Computation of metastable phases in tungsten-carbon system

  • Marios D. Demetriou
  • Nasr M. Ghoniem
  • Adrienne S. Lavine
Basic And Applied Research


Metastable phase equilibria in the W-C system are presented in the vicinity of the metastable reactions involving W2C, WC1−x , and WC. Metastable phase boundaries were obtained by reproducing the stable boundaries using optimized Gibbs energy formulations and extrapolating them into regions of metastability. Four metastable reactions were obtained: a metastable congruent melting reaction of WC at 3106 K, a metastable eutectic reaction between WC1−x and graphite at 2995 K, a metastable eutectic reaction between W2C and WC at 2976 K, and a metastable eutectic reaction between W2C and graphite at 2925 K. The reaction enthalpies and entropies associated with these transitions are also computed using the available Gibbs energy data. Furthermore, possible kinetic paths that could lead to metastability are discussed.


Metastable Phase Rapid Thermal Processing Multilayer Thin Film Metastable Phase Diagram Metastable Phase Equilibrium 
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  1. 1.
    E. Rudy: “Compendium of Phase Diagram Data,” Report No. AFML-TR-65-2, Part V, Air Force Materials Laboratory, Wright-Patterson Air Force Base, OH, 1969, pp. 192–97.Google Scholar
  2. 2.
    B. Uhrenius: “Calculation of the Ti-C, W-C, and Ti-W-C Phase Diagrams,” CALPHAD, 1984, 8(2), pp. 101–19.CrossRefGoogle Scholar
  3. 3.
    P. Gustafson: “Thermodynamic Properties of the Co-W-C System,” Mater. Sci. Technol., 1986, 2, pp. 653–58.Google Scholar
  4. 4.
    T. Johansson and B. Uhrenius: “Phase Equilibria, Isothermal Reactions, and a Thermodynamic Study in the Co-W-C System at 1150 °C,” Met. Sci., 1978, Feb, pp. 83–94.Google Scholar
  5. 5.
    F. Guillermet: “Thermodynamic Properties of the Co-W-C System,” Metall. Trans. A, 1989, 20A, pp. 935–56.ADSGoogle Scholar
  6. 6.
    W. Huang and M. Selleby: “Thermodynamic Assessment of the Nb-W-C System,” Z. Metallkd., 1997, 88(1), pp. 55–62.Google Scholar
  7. 7.
    K. Frisk: “A Thermodynamic Analysis of the Ta-W-C and the Ta-W-C-N Systems,” Z. Metallkd., 1999, 90(9), pp. 704–11.Google Scholar
  8. 8.
    G.M. Lamble, S.M. Heald, D.E. Sayers, E. Ziegler, and P.J. Viccaro: “Glancing Angle EXAFS Investigations of the Effects of Annealing on W-C Multilayer Composition,” Physica B, 1989, 158, pp. 672–73.CrossRefADSGoogle Scholar
  9. 9.
    T. Oshino, D. Shindo, M. Hirabayashi, E. Aoyagi, and H. Nikaido: “Transmission Electron Microscopy Study on Microstructure of Tungsten/Carbon Multilayer Films,” Jpn. J. Appl. Phys., 1989, 28(10), pp. 1909–914.CrossRefADSGoogle Scholar
  10. 10.
    J. Gonzalez-Hernandez, B.S. Chao, and D.A. Pawlik: “Characterization of As-Prepared and Annealed W/C Multilayer Thin Films,” J. Vac. Sci. Technol. A, 1992, 10(1), pp. 145–51.CrossRefADSGoogle Scholar
  11. 11.
    J. Luthin and Ch. Linsmeier: “Carbon Films and Carbide Formation on Tungsten,” Surf. Sci., 2000, 454–56, pp. 78–79.CrossRefGoogle Scholar
  12. 12.
    D. Tu, S. Chang, C. Chao, and C. Lin: “Tungsten Carbide Phase Transformation During the Plasma Spray Process,” J. Vac. Sci. Technol. A, 1985, 3(6), pp. 2479–482.CrossRefADSGoogle Scholar
  13. 13.
    V. Verdon, A. Karimi, and J.-L. Martin: “A Study of High Velocity Oxy-Fuel Thermally Sprayed Tungsten Carbide Based Coatings. Part 1: Microstructures,” Mater. Sci. Eng. A., 1998, A246, pp. 11–24.Google Scholar
  14. 14.
    Y. Suda, T. Nakazono, K. Ebihara, K. Baba, and R. Hatada: “Properties of WC Films Synthesized by Pulsed YAG Laser Deposition,” Mater. Chem. Phys., 1998, 54, pp. 177–80.CrossRefGoogle Scholar
  15. 15.
    S. Sharafat, A. Kobayashi, S. Chen, and N.M. Ghoniem: “Production of High-Density Ni-Bonded Tungsten Carbide Coatings Using an Axially Fed DC-Plasmatron,” Surf. Coat. Technol., 2000, 130, pp. 164–72.CrossRefGoogle Scholar
  16. 16.
    M.D. Demetriou, N.M. Ghoniem, and A.S. Lavine: “Kinetic Modeling of Phase Selection during Non-Equilibrium Solidification of a Tungsten-Carbon System,” Acta Mater., 2002 50(6), pp. 1421–432.CrossRefGoogle Scholar
  17. 17.
    J.H. Perepezko and W.J. Boettinger: “Use of Metastable Phase Diagrams in Rapid Solidification,” Mater. Res. Soc. Symp. Proc., 1983, 19, pp. 223–40.Google Scholar
  18. 18.
    C.H.P. Lupis: Chemical Thermodynamics of Materials, Elsevier, New York, 1983, pp. 56, 332.Google Scholar
  19. 19.
    R.L. Burden and J.D. Fairs: Numerical Analysis, 5th ed., PWS, Boston, 1993, pp. 56, 553.MATHGoogle Scholar
  20. 20.
    B. Sundman, B. Jansson, and J-O. Anderson: “The Thermo-Calc Databank System,” CALPHAD, 1985, 9, pp. 153–90.CrossRefGoogle Scholar
  21. 21.
    F. Spaepen: “A Structural Model for the Solid-Liquid Interface in Monoatomic Systems,” Acta Metall., 1975, 23, pp. 729–43.CrossRefGoogle Scholar
  22. 22.
    M.D. Demetriou: Ph.D. Dissertation, University of California, Los Angeles, 2001.Google Scholar

Copyright information

© ASM International 2002

Authors and Affiliations

  • Marios D. Demetriou
    • 1
  • Nasr M. Ghoniem
    • 1
  • Adrienne S. Lavine
    • 1
  1. 1.Mechanical & Aerospace Engineering DepartmentUniversity of CaliforniaLos Angeles, Los Angeles

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