High-throughput evaluation of diffusion properties in fcc Co-Fe-X (X=V/Mn) alloys

Abstract

Given the critical role of diffusion in material design, particularly its relationship with composition and structure, this study focuses on the diffusion properties in the Co-Fe-X (X=V/Mn) ternary systems, which are key sub-systems of high-entropy alloys. To carefully evaluate the interdiffusivity and atomic mobility for fcc Co-Fe-X (X=V/Mn) phase, annealing is performed at 1273, 1373, and 1473 K on 12 diffusion couples for each ternary system. EPMA (Electron Probe Microanalysis) is used to measure composition profiles after annealing. To provide more reliable diffusion coefficients, atomic mobilities in fcc Co-V and Fe-Mn phases are re-optimized in this work. Subsequently, by employing the composition profiles and corresponding experimental conditions, the interdiffusivity and atomic mobility for fcc Co-Fe-X (X=V/Mn) phase are efficiently calculated through high-throughput NNIM (novel numerical inverse method) embedded in CALTPP (CALculation of ThermoPhysical Properties) software. The presently assessed interdiffusivities and atomic mobilities for fcc Co-Fe-X (X=V/Mn) phase are verified to be reliable as the NNIM-predicted composition profiles, interdiffusivities together with diffusion paths are consistent with the measured data. Moreover, key diffusion characteristics related to materials design associated with the fcc Co-Fe-X (X=V/Mn) phase are obtained and analyzed, including interdiffusivities, 2D composition profiles, frequency factors, and diffusion activation energies. The obtained atomic mobilities and diffusion characteristics demonstrate high reliability through experimental validation, which not only contributes to establishing the diffusion database but also provides crucial insights for designing high-entropy alloys.