Molecular dynamics simulation for cooling rate dependence of solidification microstructures of silver

A molecular dynamics simulation study has been performed to investigate the solid microstructures of Ag at room temperature resulted from rapid solidification with six cooling rates by using Quantum Sutton–Chen (QSC) many body potential. Several structural analysis methods have been employed to characterize and analyze the atomic configurations in the system. The results reveal that as the cooling rate γ ⩾ 1.0 × 1013 K/s, an amorphous structure can be obtained; as the cooling rates in the range of γ = 5.0 × 1012 ∼ 1.38 × 1011 K/s, the coexistence structures of the meta-stable hcp with stable fcc configurations can be formed with phase separating or layering structures. Moreover, by using the 3D graphics technology, the arrangement of atoms in the system reveals that the phase separating occurs before the layering structures can be formed following the cooling rate decreasing. And an interesting layering structures have been found, in which the central atoms of fcc and hcp basic clusters are arranged by alternate close-packed-layers with a new repeating sequence ABCB.