Crystal Growth of BCC Titanium from the Melt and Interfacial Properties: A Molecular Dynamics Simulation Study

Abstract

The crystal growth kinetics as well as interfacia properties of Titanium (Ti) are studied, using molecular dynamics (MD) computer simulation. The interactions between the Ti atoms are modelled via an embedded atom method (EAM) potential. First, the free solidification method (FSM) is used to determine the melting temperature Tm at zero pressure where the transition from liquid to body-centered cubic (bcc) crystal occurs. From the simulations with the FSM, also the kinetic growth coefficients are determined for different orientations of the crystal, analyzing how the coupling to the thermostat affects the estimates of the growth coefficients. At Tm, anisotropic interfacial stiffnesses and free energies as well as kinetic growth coefficients are determined from capillary wave fluctuations. The so obtained growth coefficients from equilibrium fluctuations and without the coupling of the system to a thermostat agree well with those extracted from the FSM calculations.