The BCC-HCP transition temperature in titanium metal using the classical molecular dynamics method

Abstract

Molecular dynamics is carried out in order to calculate the component of Helmholtz free energy of the hcp and the bcc titanium at temperature from 300K to 1,300K. The internal energy difference is calculated from the potential energy difference. The Finnis-Sinclair potential energy is chosen to represent the potential energy of titanium. The total entropy consists of the electronic entropy and the vibrational entropy including harmonic and anharmonic vibrational entropy. The transition temperature is identified at 880K where Helmholtz free energy difference between the two phases is equal to zero. This finding is in agreement with experiments.