MATERIALS
Thermodynamic properties of melts of binary and ternary systems containing Fe, Mn, Si or Ti
The thermodynamic properties of the melts of the Fe–Mn(Ti)–Si, Fe–Mn–Ti, and Mn–Si–Ti ternary systems at 1873 K were studied using the “geometric” and “analytical” Redlich-Kister-Mujian models from reliable analogous data for binary boundary subsystems. Special attention is paid to the precise thermodynamic properties of melts of the Fe-Mn, Fe-Si, and Mn-Si systems, with analysis of new data for the Si-Ti, Fe-Ti, and Mn-Ti systems. Very negative deviations from ideal solutions were established for the activities of the components in melts of the Fe-Mn-Si system. In the melts of the Fe–Mn(Ti)–Si, Fe–Mn–Ti, and Mn–Si–Ti ternary systems, the minimum mixing enthalpies are observed in binary melts, and in the Fe–Mn–Si system, the minimum occurs in the Fe0.4Mn0.2Si ternary melt 0.4, because the double Fe(Mn)– Si subsystems make the largest contribution to the interaction energy between different atoms. This study demonstrates the ability to predict the thermodynamic behavior of ternary systems, allowing for optimization of alloy compositions and improvement of industrial processes. Calculations based on the Redlich-Kister-Mujianu model with a triple contribution of -200 kJ/mol for melts of the Fe–Mn–Si system agree with experimental data, which confirms sufficiently high accuracy predicted parameters.