An Analytical Model for Solute Segregation at Liquid Metal/Solid Substrate Interface

Abstract

In this paper, we present an analytical model for describing the equilibrium solute segregation at the interface between metallic liquid (an A–B solution, where A is solvent and B is solute) and a solid substrate (S) using approaches of thermodynamics and statistical mechanics. This analytical model suggests that the interfacial solute segregation is governed by the difference in interfacial energies between the pure B/S and pure A/S interfaces, the heat of mixing of the A–B solution and the difference in entropies of fusion between pure solute and solvent. The calculated solute segregations at the interface in the liquid Al-Ti/TiB2 and liquid Sn-Al/Al2O3 systems are in qualitative agreement with the experimental observations. It is demonstrated that the present analytical model can be used to predict the solute segregation at the liquid/substrate interface, at least qualitatively.