Experimental investigation and thermodynamic calculation of the Fe–Mg–Mn and Fe–Mg–Ni systems

Abstract

Abstract Based on the thermodynamic calculations extrapolated from the corresponding binary sub-systems, four decisive alloys in the Fe–Mg–Mn system and three in the Fe–Mg–Ni system were selected and prepared using a powder metallurgy method to measure the isothermal sections at 500 8C in both systems. The prepared samples were annealed at 5008C, and then subjected to X-ray diffraction, optical microscopy, scanning electron microscopy with energy-dispersive X-ray spectrometry as well as electron probe microanalysis. Taking into account the presently obtained experimental data and the experimental data available in the literature, thermodynamic modeling was performed for the above systems. It was found that a direct extrapolation from the corresponding three binary systems can well reproduce all the experimental data in the Fe–Mg–Mn system, while two thermodynamic parameters are needed in the Fe–Mg–Ni system to fit all the experimental data. The liquidus projections and reaction schemes for the Fe–Mg–Mn and Fe–Mg–Ni systems are also presented.