Thermodynamic investigation of the Al-Fe-Mn system over the whole composition and wide temperature ranges

Abstract

The Al-Fe-Mn system is a core system for both aluminum alloys and lightweight steels. In the present work its phase relations were studied over the entire composition range between RT and well above the melting temperature using the CALPHAD method. For the first time the stable γ1 phase and the metastable φ phase were successfully introduced into the description of the Al-Mn binary system. The wide solubility ranges of the third element in the binary intermetallic compounds, such as Al6Mn, Al13Fe4, γ1 and γ2, were reproduced satisfactorily. The ternary phases, i.e. φ, ζ and D3, were reasonably well described using compound energy models. Moreover, the phase equilibria between the bcc, fcc and β-Mn phases in the Fe-Mn rich part were well predicted using the present description.