Theoretical calculation of thermodynamic data for bcc binary alloys with the embedded-atom method

Abstract

The dilute-limit heats of solution for all binary alloys of six bcc transition metals (V, Nb, Ta, Mo, W, and Fe) have been calculated with the analytic embedded-atom model for bcc pure metals by Johnson and Oh. Cubic equations are proposed and used for providing a smooth cutoff for the calculated potential and electron density functions between second- and third-nearest neighbors in the calculation. The heats of formation for all of the binary alloys of these six bcc metals for the whole compositional range and the intermetallic compounds ${\mathit{A}}_3$B, AB, and ${\mathit{AB}}_3$ are also calculated. The dilute-limit heats of solution are generally in agreement with available experimental values except for Ta in W and W in Ta. The heats of formation agree well with available experimental data, ab initio calculations by Colinet, Beesound, and Pasturrel, and thermodynamic calculations with the Miedema model for Mo-Ta, Mo-Nb, and Fe-V. The heats of formation are in good agreement with thermodynamic calculations with the Miedema model for W-V, Nb-V, Ta-V, Fe-W, Mo-W, Ta-Nb, Fe-Nb, Fe-Ta, and Mo-V alloy systems. There are, however, significant differences between the heats of formation for the present work and calculations with the Miedema model for the Ta-W, Nb-W, and Fe-Mo alloy systems.