Ab initio calculation of the BCC Fe–Al–Mo (Iron–Aluminum–Molybdenum) phase diagram: Implications for the nature of the τ2 phase

Ordering phase relationships in ternary iron aluminides

“…In a previous work by some of the present authors these differences were traced back to the different equilibria observed in the stable or metastable binary bcc equilibrium in the Fe-M systems: Fe-Ti has a stable B2 phase at the center of the phase diagram, while Fe-Mo has a miscibility gap, no ordered bcc superlattices being observed, not even as metastable phases [9]. The aim of the present work is to test this hypothesis by analyzing also the metastable equilibria in bcc Fe-Al-Nb system, which can be considered as an intermediate case in relation to Fe-Al-Mo and Fe-Al-Ti.…”

“…The procedure used here is equivalent to the one employed in a previous work [9]. For easy reference, we rewrite the main equations for the present context.…”

Combined ab initio and experimental study of A2 + L21 coherent equilibria in the Fe–Al–X (X = Ti, Nb, V) systems

“…Only a few works report ab initio ternary phase diagram calculations, these are from Alonso and Rubiolo [33], Lechermann et al [34] and Sodré et al [35] on modeling the BCC TieAleMo, BCC-FCC NieFeeAl and BCC FeeAleMo systems, respectively. All of them use the truncation point for the cluster expansion set to a lower approximation (the tetrahedron cluster, irregular for BCC and regular for FCC).…”

Modified embedded-atom method interatomic potential for the Fe–Al system

“…The ordering transition temperature [33] that changes with composition and the vacancy formation energy [34,35] could be considered to determine the potential parameters or to evaluate the transferability of the potential. First-principles calculations [36][37][38][39][40][41][42][43][44][45][46][47] and empirical calculations using other many-body potentials [11][12][13] are also available for various physical properties, and those values were used mainly for comparison. Even though many other compound phases are reported on the Al-rich region of the Fe-Al phase diagram, those phases were not considered in the present work since their crystal structures were unclear or too complicated to deal with using an (semi-)empirical interatomic potential.…”