Kinetics of rapid growth and melting of Al50Ni50 alloying crystals: phase field theory versus atomistic simulations revisited *

Abstract

A revised study of the growth and melting of crystals in congruently melting Al50Ni50 alloy is carried out by molecular dynamics (MDs) and phase field (PF) methods. An embedded atom method (EAM) potential of Purja Pun and Mishin (2009 Phil. Mag. 89 3245) is used to estimate the material’s properties (density, enthalpy, and self-diffusion) of the B2 crystalline and liquid phases of the alloy. Using the same EAM potential, the melting temperature, density, and diffusion coefficient become well comparable with experimental data in contrast with previous works where other potentials were used. In the new revision of MD data, the kinetics of melting and solidification are quantitatively evaluated by the ‘crystal-liquid interface velocity-undercooling’ relationship exhibiting the well-known bell-shaped kinetic curve. The traveling wave solution of the kinetic PF model as well as the hodograph equation of the solid-liquid interface quantitatively describe the ‘velocity-undercooling’ relationship obtained in the MD simulation in the whole range of investigated temperatures for melting and growth of Al50Ni50 crystals.