A third generation CalPhaD assessment of the Fe–Mn–Ti system Part II: The ternary system Fe–Mn–Ti

The ternary Fe–Mn–Ti system plays an important role in the development of several different functional and structural materials, which can be applied e.g., as shape-memory alloys or for hydrogen storage. Since the corresponding materials properties are closely connected to the thermodynamic behavior of the individual phases in the alloys, thermodynamic calculations can provide useful information for a sustainable and straightforward alloy development. Therefore, a 3rd generation CalPhaD description of the Fe–Mn–Ti system was developed, which applies advanced sublattice models for several phases such as A12, A13 and C14, to ensure physically meaningful estimations of their thermodynamic properties. Moreover, the modelling was supported by experimental investigations on the phase relations in the ternary Fe–Mn–Ti system, based on diffusion-couple experiments at 800, 900 and 1000 °C. During these experiments, several local phase equilibria between A1, A2, A3, A12, B2, C14 and MnTi1-x were established and subsequently investigated using SEM/BSE-imaging, EPMA and EBSD.