Computation of metastable phases in tungsten-carbon system

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

Abstract

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.

Keywords

Metastable Phase Rapid Thermal Processing Multilayer Thin Film Metastable Phase Diagram Metastable Phase Equilibrium 

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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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