Surface Transport in Pre--Melted Films with Application to Grain--Boundary Grooving

TL;DR

This paper introduces a new model for surface transport in premelted films near melting points, applicable to various materials, and demonstrates its use in modeling grain boundary grooving, reproducing classical equations and deriving a temperature-dependent transport coefficient.

Contribution

A novel model of surface transport in premelted films that generalizes classical theories and includes a temperature-dependent transport coefficient.

Findings

Reproduces Mullins's classical equation asymptotically

Identifies a modified microscopic contact angle at the groove root

Derives an explicit, temperature-dependent transport coefficient

Abstract

We present a new model of surface transport in premelted films that is applicable to a wide range of materials close to their melting point. We illustrate its use by applying it to the evolution of a grain boundary groove in a high vapour pressure material and show that Mullins's classical equation describing transport driven by gradients in surface curvature is reproduced asymptotically. The microscopic contact angle at the groove root is found to be modified over a thin boundary layer, and the apparent contact angle is determined. An explicit transport coefficient is derived that governs the evolution rate of systems controlled by surface transport through premelted films. The transport coefficient is found to depend on temperature and diverges as the bulk melting temperature is approached.