Thermodynamic modelling of the σ and μ phases in several ternary systems containing Co, Cr, Fe, Mo, Re and W

In the framework of the CALPHAD approach to the thermodynamic modelling of solid solution phases inmulticomponent alloy systems, the Compound Energy Formalism has been successfully used for severalyears. However, for a few important phases with relatively complex crystal structure such assandmphases, many different descriptions have been used by different authors. In this paper we propose whatis, in our opinion, the best models to be adopted for these two phases, especially when they are includedin large multicomponent databases. Our choice is supported by a series of successful applications to themodelling of a selection of ternary systems, namely CreFeeMo, CoeCreMo, CoeCreFe, CreFeeW and CoeCr-Re, wheres,mor both of them are stable.