Characterization and visualization of grain boundary disconnections

TL;DR

This paper presents a novel atomic-level visualization method for dislocations and disconnections at grain boundaries, enhancing understanding of their structure and interactions in materials like tungsten and copper.

Contribution

The paper introduces an extension of the Nye tensor calculation to visualize grain boundary disconnections at atomic resolution, applicable to different crystal structures.

Findings

Effective visualization of disconnections in tungsten and copper

Characterization of grain boundary phase nuclei in tungsten

Method enables study of dislocation interactions with grain boundaries

Abstract

We introduce a method to visualize dislocations along grain boundaries at the atomic level. It uses an atomic-level Nye tensor, representing the dislocation density. To calculate the Nye tensor at grain boundaries, we extend the Hartley-Mishin strain gradient calculation to the displacement shift complete lattice. We show that the method is effective in visualizing disconnections and the dislocation content of grain boundary phase junctions in body-centered cubic tungsten, as well as face-centered cubic copper. In addition, we use the method to characterize the morphology of a two-dimensional grain boundary phase nucleus in a symmetric tilt grain boundary in tungsten. This method can be applied to both bulk dislocations and grain boundary disconnections, which makes it ideal for studying the interactions and reactions of bulk dislocations with grain boundaries, and grain boundary disconnections.