Effects of grain boundary on the sources of size effects

TL;DR

This paper investigates how grain boundaries influence the mechanisms behind size effects in materials, revealing that at larger scales, GBs alter dislocation patterns and increase hardness.

Contribution

It provides a novel analysis of the role of grain boundaries across different length scales, focusing on their impact on dislocation structures and size-dependent hardness.

Findings

Grain boundaries change dislocation patterns at larger scales.

GBs cause dislocation pile-up near boundaries, increasing hardness.

The study highlights the scale-dependent influence of GBs on size effects.

Abstract

The present work investigates the role of grain boundary (GB) on the sources of size effects. Up to now, several studies have been conducted to address the role of GBs in size effects from the atomistic point of view. However, a study which addresses the role of GB on different governing mechanisms of size effects as the sample length scale varies has not been presented yet. The results show that the main role of GB at larger length scale is to change the pattern of dislocation structure in a way that the dislocations are piled up near the GB which increases the hardness.