Computer simulations of the interface zone structure in binary eutectic

TL;DR

This study uses molecular dynamics simulations to analyze the structure and behavior of the interface zone in binary AgCu eutectic, revealing temperature-dependent phase separation, diffusion zone formation, and contact melting phenomena.

Contribution

It provides detailed simulation insights into the interface structure and phase behavior of binary eutectics near the melting point, highlighting the formation of a diffusion zone.

Findings

Steady disordered diffusion zone forms at the interface during solid-state equilibrium.

The diffusion zone widens and particle diffusivities increase as temperature approaches the eutectic point.

Above the eutectic point, contact melting occurs without steady zone formation.

Abstract

Molecular dynamics simulations of the interface structure in binary AgCu eutectic were performed by using the realistic EAM potential. In simulations, we examined such quantities as the time dependence of the total energy in the process of equilibration, the probability distributions, the composition profiles for the components, and the component diffusivities within the interface zone. It is shown that the equilibrium in the solid state associated with the complete phase separation in binary eutectic is accompanied by formation of the steady disordered diffusion zone at the boundary of the crystalline components. At higher temperatures, closer to the eutectic point, the increase in the width of the steady diffusion zone is observed. The particle diffusivities grow therewith to the numbers typical for the liquid phase. Above the eutectic point, the steady zone does not form, instead, the complete contact melting in the system occurs. The results of simulations indicate that during the temperature increase the phenomenon of contact melting is preceded by the similar process spatially localized in the vicinity of the interface.