Thermodynamic assessment and experimental investigation of the systems Al–Fe–Mn and Al–Fe–Mn–Ni

The ternary Al–Fe–Mn and the quaternary Al–Fe–Mn–Ni systems were re-assessed/assessed with special emphasis on compositions relevant for Fe-based shape memory alloys (SMAs), to further improve materials properties and to reliably predict phase transformation in these systems. The thermodynamic assessment was based on literature data, as well as experimental investigations regarding the phase equilibria formed between the phases A1, A2, B2 and β-Mn. Key isothermal sections were studied at 725 and 1000 °C in the Al–Fe–Mn system and at 1000 and 1175 °C in the Al–Fe–Mn–Ni system, respectively. For the quaternary Al–Fe–Mn–Ni system, additional diffusion-couple experiments were conducted to investigate target regions of the phase diagram. Calculations based on the present description are in excellent agreement with the data available in literature and the experimental investigations of the present work for both, the Al–Fe–Mn and the Al–Fe–Mn–Ni systems.