Thermodynamic evaluation of the phase equilibria and glass-forming ability of the Fe-Si-B system

Tatsuya Tokunaga, Hiroshi Ohtani, Mitsuhiro Hasebe

Research output: Contribution to journalArticlepeer-review

30 Citations (Scopus)


A thermodynamic study has been carried out on the Fe-Si-B ternary system, which is important in the development of transformer core materials and Ni-based filler metals. A regular solution approximation based on the sublattice model was adopted to describe the Gibbs energy for the individual phases in the binary and ternary systems. Thermodynamic parameters for each phase were evaluated by combining the experimental results from differential scanning calorimetry with literature data. The evaluated parameters enabled us to obtain reproducible calculations of the isothermal and vertical section diagrams. Furthermore, the glass-forming ability of this ternary alloy was evaluated by introducing thermodynamic quantities obtained from the phase diagram calculations into Davies-Uhlmann kinetic formulations. In this evaluation, the time-temperature-transformation (TTT) curves were obtained, which are a measure of the time required to transform to the minimum detectable mass of crystal as a function of temperature. The critical cooling rates calculated on the basis of the TTT curves enabled us to evaluate the glass-forming ability of this ternary alloy. The results show good agreement with the experimental data in the compositional amorphization range.

Original languageEnglish
Pages (from-to)354-362
Number of pages9
JournalCalphad: Computer Coupling of Phase Diagrams and Thermochemistry
Issue number4
Publication statusPublished - 2004 Dec
Externally publishedYes


  • Amorphous
  • Glass-forming ability
  • Iron-silicon-boron
  • Phase equilibria

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Computer Science Applications


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