Connecting a bulk material's microscopic defects to its macroscopic properties is an age-old problem in materials science. Long-range interactions between dislocations (line defects) are known to play a key role in how materials deform or melt, but we lack the tools to connect these dynamics to the macroscopic properties. We introduce time-resolved dark-field X-ray microscopy to directly visualize how dislocations move and interact over hundreds of micrometers, deep inside bulk aluminum. With real-time movies, we reveal the thermally-activated motion and interactions of dislocations that comprise a boundary, and show how weakened binding forces inhomogeneously destabilize the structure at 99% of the melting temperature. Connecting dynamics of the microstructure to its stability, we provide important opportunities to guide and validate multiscale models that are yet untested.
@article{arxiv.2009.05083,
title = {In-Situ Visualization of Long-Range Defect Interactions at the Edge of Melting},
author = {Leora E. Dresselhaus-Marais and Grethe Winther and Marylesa Howard and Arnulfo Gonzalez and Sean R. Breckling and Can Yildirim and Philip K. Cook and Mustafacan Kutsal and Hugh Simons and Carsten Detlefs and Jon H. Eggert and Henning Friis Poulsen},
journal= {arXiv preprint arXiv:2009.05083},
year = {2023}
}