Non-isothermal kinetic analysis on the phase transformations of Fe–Co–V alloy

Abstract

In this study, occurrence of different phase transformations was investigated in a FeCo-7wt% V alloy upon heating to 1200°C by the dilatometry method at different heating rates (5, 10, and 15°Cmin−1). It was found that four phase transformations (including B2-type atomic ordering in α phase, first stage of polymorphic transformation (α→αr+γ), ordering to disordering, and second stage of polymorphic transformation (αr→γ) occur in this alloy up to 1200°C. Two isoconversional methods, as Starink and Friedman, were used to determine variation of the activation energy with temperature, E(T). Moreover, the empirical kinetic triplets (E, A, and g(α)) were calculated by the invariant kinetic parameters (IKP) method and fitting model.