Effect of vanadium on atomic ordering characteristics and anti-phase boundary energies of B2–FeCo alloys

Effect of V on the energetical and structural characteristics of atomic ordering processes of B2–FeCo intermetallics have been investigated via electronic theory of multi-component alloys combined with Monte Carlo (MC) simulations. Emphasis has been placed on the variation of anti-phase boundary (APB) energies with V content and temperature to establish a relationship between ductility and atomic ordering characteristics of (FeCo)100−xVx (x = 0–5 at%) alloys. It was shown that APB energies are highly affected by actual degree of long range order (LRO) and also dissolution mode of V alloying element atoms. Results of present simulation reveals that partially ordered (FeCo)100−xVx alloy having x = 2 at% V facilitates the highest loss in {110} APB energy in temperature range of 300–750 K and yields drastic increase in <111> {112} APB energies with increasing concentration of V due to pinning effect. Owing to the lowest APB energy of {110} planes, (FeCo)98V2 alloy would be predicted to display higher ductility, in agreement with experimental observations, relative to binary B2–FeCo intermetallic due to more independent movement of a/2 <111> partials at low temperatures.