Methods to Quantify Dislocation Behavior with Dark-field X-ray Microscopy Timescans of Single-Crystal Aluminum

TL;DR

This paper introduces a semi-automated method to analyze dark-field X-ray microscopy images, enabling detailed tracking and statistical characterization of dislocation behavior in single-crystal aluminum at high temperatures.

Contribution

It presents a novel semi-automated approach for isolating, tracking, and quantifying dislocation dynamics from DFXM images, advancing the analysis of defect evolution in materials.

Findings

Dislocation velocity and orientation can be quantitatively measured.

The method successfully tracks dislocation evolution near melting temperature.

Analysis enhances understanding of defect behavior in high-temperature conditions.

Abstract

Crystal defects play a large role in how materials respond to their surroundings, yet there are many uncertainties in how extended defects form, move, and interact deep beneath a material's surface. A newly developed imaging diagnostic, dark-field X-ray microscopy (DFXM) can now visualize the behavior of line defects, known as dislocations, in materials under varying conditions. DFXM images visualize dislocations by imaging the very subtle long-range distortions in the material's crystal lattice, which produce a characteristic adjoined pair of bright and dark regions. Full analysis of how these dislocations evolve can be used to refine material models, however, it requires quantitative characterization of the statistics of their shape, position and motion. In this paper, we present a semi-automated approach to effectively isolate, track, and quantify the behavior of dislocations as composite objects. This analysis drives the statistical characterization of the defects, to include dislocation velocity and orientation in the crystal, for example, and is demonstrated on DFXM images measuring the evolution of defects at 98$\%$ of the melting temperature for single-crystal aluminum, collected at the European Synchrotron Radiation Facility.