Contribution of thermal conductivity to the crystal-regrowth velocity of embedded-atom-method-modeled metals and metal alloys

Abstract

The regrowth velocity of a crystal from a melt depends on contributions from the thermal conductivity, heat gradient, and latent heat. The relative contributions of these terms to the regrowth velocity of the pure metals copper and gold during liquid-phase epitaxy are evaluated. These results are used to explain how results from previous nonequilibrium molecular-dynamics simulations using classical potentials are able to predict regrowth velocities that are close to the experimental values. Results from equilibrium molecular dynamics showing the nature of the solid-vapor interface of an embedded-atom-method-modeled ${\mathrm{Cu}}_{57}$ ${\mathrm{Ni}}_{43}$ alloy at a temperature corresponding to 62% of the melting point are presented. The regrowth of this alloy following a simulation of a laser-processing experiment is also given, with use of nonequilibrium molecular-dynamics techniques. The thermal conductivity and temperature gradient in the simulation of the alloy are compared to those for the pure metals.