A third generation CalPhaD assessment of the Fe–Mn–Ti system part I: The binary subsystems Fe–Mn, Fe–Ti and Mn–Ti

Abstract

The binary systems Fe–Mn, Fe–Ti and Mn–Ti play remarkable roles in the development of numerous structural and functional materials. As their properties are closely related to the thermodynamic behavior of the phases in the corresponding alloys, the calculation of phase equilibria is crucial for a sustainable and straightforward alloy development. In that course, thermodynamic descriptions within the framework of 3rd generation CalPhaD databases of the binary systems Fe–Mn, Fe–Ti and Mn–Ti were developed. To ensure physically meaningful estimations of the individual thermodynamic properties, advanced sublattice models for several phases, such as A12 (α-Mn), A13 (β-Mn) and C14 (hexagonal Laves phase) were applied. The modelling was supported by heat-capacity measurements for the C14–Mn2Ti phase, to provide a thermodynamically profound basis for a subsequent description of the phase relations. Through the combination of the advanced models and reliable thermodynamic data for each system, thermodynamic descriptions could be derived, which facilitate reliable calculations from 0 K to far beyond the melting point of the individual alloys.