A thermodynamic assessment of the Cr-Mo system using CE-CVM

A thermodynamic assessment of the condensed phase region of the Cr-Mo system has been carried out on the basis of available experimental thermodynamic and phase equilibria data. The Gibbs energy of the BCC_A2 solid phase was described by using octahedron-rhombohedron-cube (ORC) approximation of the Cluster Expansion and Cluster Variation Methods (CE-CVM), while a sub-regular solution model was used for describing Gibbs energy of the liquid phase. An optimal set of parameters has been obtained for describing the Gibbs energies of the liquid and solid phases in the Cr-Mo binary system by simultaneous optimization of all experimental data. The calculated phase diagram and thermodynamic properties are in good agreement with experimental data. The relevance of CE-CVM has been demonstrated in the present case by computing first to fifth neighbor short range order (sro) parameters of the solid phase as a function of composition at various temperatures.