The fcc/hcp relative phase stability in the Fe-Mn-Co system: Martensitic transformation temperatures, assessment of Gibbs energies and thermodynamic calculation of T0lines

Abstract

In this paper the results of a systematic study of the fcc/hcp relative phase stability in the Fe-Mn-Co system are presented, which is based on new, extensive measurements of the martensitic transformation temperatures. The whole range of compositions where the transformation occurs has now been covered. A thermodynamic analysis of the experimental information based in Gibbs energy modelling of the Fe-Mn-Co, Fe-Mn and Fe-Co systems is performed. The T0temperatures for the Fe-Mn-Co system are established. It is shown how ternary information can be utilized to assess the Gibbs energy function of the hcp phase, which is not stable in the Fe-rich region of the binary Fe-Co system.