THERMODYNAMIC CALCULATIONS OF HIGH ENTROPY (FE-MN) BINARY ALLOY SYSTEM USING CALPHAD METHOD BASED ON THERMO-CALC PACKAGE AND PBINE,FEDATE DATABASES.

Abstract

The thermodynamic analysis and calculations of the high entropy metastable binary alloy ironmanganese system have been carried out using the CALPHAD (Calculation of phase Diagram) method based on THERMO-CALC (thermodynamic calculations) package and FEDATE database. Thermodynamic analysis contain the assessment and calculation of phase diagram, Gibbs energy of mixing, excess Gibbs energies, thermodynamic molar activities, coefficient of activities, partial and integral values of enthalpy for Fe-Mn alloy system at three elevated temperatures 1200K, 1225K, and 1250K.The entropy of the said alloy system is calculated by showing linear accordance with temperature. The sudden increase is found in enthalpy curve due to overlapping of grain boundaries of the system. The high enthalpy shows increasing heat contents of the said alloy system with increasing temperature range. The alloy shows a positive deviation from Vegard’s law, Henry’s law and corresponding negative deviation from Raoults’s law ideal Gibbs curve. The obtained results show that the ferromagnetic states of Fe-Mn alloy is the most stable state FCC_A1#1. For Mn and Fe system, the phase equilibria show activity curve data for solid state and show ideal characteristics behaviors. Small positive deviation from Henry’s law was observed from the ideal curve. The alloy shows equilibrium and good stability.