Investigations of interface phenomena via atomistic simulation

Abstract

In the first section of the thesis we examine a phenomenon known as grain boundary (GB) pre-melting in binary systems. Many GBs develop highly disordered, liquid-like structures at high temperatures. In alloys, this effect is less understood as it can be fueled by solute segregation to the boundary. In single component systems, pre-melted GBs are often modeled by a thin liquid layer located between two solid-liquid interfaces interacting via a disjoining potential. We have extended this formalism to binary systems and proposed a single analytical form of the disjoining potential that describes repulsive, attractive and intermediate interactions. The potential is verified by Monte Carlo simulations of three different GBs in Cu-Ag alloys modeled using an embedded atom potential. The proposed approach is generic and can be applied to other alloys in the future.