Thermodynamic properties of Mn-Y-Si(Ge,Sn, Pb,C) melts

The effect of Group IVA elements on the integral enthalpy of mixing of Mn-Y-Si(Ge, Sn, Pb, C) melts has been studied using the mixing enthalpies of Mn-Y-Si(Ge) melts determined earlier by calorimetry at 1770 ± 5 K. Since the thermochemical properties of Mn-Y-C(Sn, Pb) melts are unexplored, they have been calculated by the Bonnier-Caboz method using reliable data for the constituent binary systems. To this end, we have performed critical evaluation of the phase diagrams and thermochemical data for the constituent binary systems and have compared the enthalpies of formation of solid Δ_f H and liquid Δ_mix H binary alloys. The results indicate that, among liquid Mn-Y-IVA alloys, the formation of Mn-Y-Ge melts is the most exothermic. The thermochemical properties of all the ternary alloys examined are determined by the properties of the Y-Si(Ge, Sn, Pb, C) constituent binary systems, which have the highest exothermic mixing enthalpies.