Molecular dynamics calculations of the crystal-melt interfacial mobility for hexagonal close-packed Mg

The kinetics of crystallization from the melt is investigated for hcp Mg employing molecular dynamics simulations based on a recently developed embedded-atom-method interatomic potential. The interface mobility (μ), defined as the constant of proportionality between interface velocity and undercooling, is calculated for the three high-symmetry orientations (0001), (101̅ 0), and (112̅ 0). The magnitudes of the interface mobilities are found to lie in the range of 40–80 cm∕s∕K. The mobilities μ_{101̅ 0} and μ_{112̅ 0} are found to be of comparable magnitude and approximately 1.7 times larger than μ₀₀₀₁. The calculated dependence of μ on interface normal is discussed within the framework of the kinetic density-functional theory (DFT) formulation of Mikheev and Chernov.