Atomic-scale interaction of a crack and an infiltrating fluid

TL;DR

This study examines how infiltrating fluids at the atomic scale affect crack propagation and fracture toughness, providing insights into surface energy modifications due to surface adsorbates.

Contribution

It introduces an atomic-level simulation approach to analyze the impact of fluids on crack behavior, validating the Orowan hypothesis with universal scaling trends.

Findings

Fracture toughness decreases with increased surface energy reduction.

Fluid particle size and surface energy significantly influence crack propagation.

Universal behavior observed across different fluid-solid interaction parameters.

Abstract

In this work we investigate the Orowan hypothesis, that decreases in surface energy due to surface adsorbates lead directly to lowered fracture toughness, at an atomic/molecular level. We employ a Lennard-Jones system with a slit crack and an infiltrating fluid, nominally with gold-water properties, and explore steric effects by varying the soft radius of fluid particles and the influence of surface energy/hydrophobicity via the solid-fluid binding energy. Using previously developed methods, we employ the J-integral to quantify the sensitivity of fracture toughness to the influence of the fluid on the crack tip, and exploit dimensionless scaling to discover universal trends in behavior.