Thermodynamic analysis of glass formation in Fe-B system

A thermodynamic optimisation of the Fe-B system has been carried out in order to model metastable phases. Amorphous and Fe3B metastable phases have been considered in the assessment in order to describe, from a thermodynamic point of view, the well known glass forming ability of this system. An excess specific heat has been considered for the liquid alloys in order to take into account ordering processes on undercooling. The glass transition has been considered as a second order transition between undercooled liquid and amorphous phases. The effect of lattice stabilities on assessment has been discussed considering different descriptions for the free energy of undercooled pure liquid Fe. The calculated stable and metastable phase diagrams are in good agreement with experimental data, as well as invariant equilibria and thermodynamic properties. The results evidence the existence of an excess specific heat for glass forming Fe-B liquid alloys, which allows a reasonable description of thermodynamic functions for all phases in a wide temperature range.