Hole-initiated melting process of thin films

TL;DR

This study investigates the melting behavior of thin films initiated by small holes, revealing counter-intuitive effects of wetting and boundary conditions through numerical and experimental methods, with implications for understanding capillary-driven melting processes.

Contribution

It introduces a combined numerical and experimental analysis of hole-initiated melting in thin films, highlighting novel effects of wetting and boundary influences on melting behavior.

Findings

Melting point is elevated with partial wetting even at small contact angles.

Melting may start from the outer boundary rather than the hole.

Complex melting scenarios include morphology transitions and a range of melting points.

Abstract

We perform numerical and experimental studies on the melting process of thin films initiated by a small hole. The presence of a non-trivial capillary surface, namely the liquid/air interface, leads to a few counter-intuitive results: (1) The melting point is elevated if the film surface is partially wettable, even with a small contact angle. (2) For a film that is finite in size, melting may prefer to start from the outer boundary, rather than a hole inside. (3) More complex melting scenario may arise, including morphology transitions, and the "de facto" melting point being a range instead of a single value. These are verified by experiments on melting alkane films between silica and air. This work continues a series of investigations on the capillary aspects on melting. Both our model and analysis approach can be easily generalized to other systems.