Atomic-scale analysis of martensitic transformation in titanium alloyed with vanadium .1. Verification of the embedded-atom method model

The embedded-atom method type interatomic potentials for h.c.p. titanium and b.c.c, vanadium, originally proposed by Johnson and coworkers, were modified in order to be able to model both the b.c.c. and the h.c.p. structures and the phase transformation between the two in titanium-base Ti-V alloys. The reliability of the modified potentials was tested with respect to lattice dynamics (the phonon dispersion curves and the phonon density of states) in the two structures and with respect to the relative thermodynamic stability of the two phases as a function of temperature and the alloy composition. The model predictions are found to be in reasonable agreement with their experimental counterparts. In particular, the predicted effect of vanadium on two phonon modes, a T-1 N-point 1/2[110] phonon and T-1 [112] phonon, which play the key roles in the b.c.c. --> h.c.p. transformation, was found to be consistent with the experiment.