Final Structures of Crystallization of Liquid Copper Studied by Molecular Dynamics Simulation

Molecular dynamics simulation is performed to study the cooling rate effects on the resulting crystallization microstructure of bulk liquid copper (homogeneous nucleation). Our studies reveal that mixtures of the metastable hcp phase and most-stable fcc phase, in all sorts of proportion and in various forms such as layering and phase separation, can be obtained by controlling the cooling rate. We have also found that, below the glass forming critical cooling rate, the ratio of the number of fcc-type polyhedra to the number of hcp-type polyhedra at 0K decreases with increase of the cooling rate.