Atomic mobility evaluation and diffusion matrix for fcc_A1 Co–V–W alloys

On the basis of measured interdiffusivity matrices from our previous research and thermodynamic descriptions, atomic mobilities for fcc_A1 Co–V–W alloys were evaluated by diffusion controlled transformation software. For the purpose of verifying the reliability of the present atomic mobilities, comparisons between the predicted data containing interdiffusivity matrices, composition profiles, as well as diffusion paths and the experimental ones were conducted. The results demonstrate that presently obtained atomic mobilities can reproduce experimental data reasonably. Furthermore, three-dimensional surfaces for the diagonal interdiffusivities at 1373, 1423 and 1473 K were plotted and were compared with measured ones, from which the pre-exponential factor and activation energy for elements V and W were then derived by means of Arrhenius equation. It is worth mentioning that all of the composition profiles and diffusion paths at three temperatures can be reasonably predicted by the present atomic mobilities containing only two ternary interaction parameters. Such a high simulation accuracy is rarely reported in the literature. The present atomic mobilities contribute to computational design for novel Co-based superalloys and multi-component cemented carbides.