Influence of Light Impurities on the Crystal-Melt Interface Velocity in Ni and Ag. Molecular Dynamics Simulation

The influence of impurities of light elements (C, N, and O) on the crystal-melt interface velocity in fcc metals (Ni and Ag) has been investigated by the molecular dynamics method. Dependences of the crystallization rate on the impurity concentration are obtained. It is shown that the presence of impurities reduces significantly the crystal-melt interface velocity in metals. Impurity atoms induce local lattice strain, which leads to deceleration of the crystal-melt interface; as a rule, the stronger this strain is, the more significant the deceleration of the crystal-melt interface by impurity atoms is.