In situ visualization of long-range defect interactions at the edge of melting

• Published in: Science advances 2021-07, Vol.7 (29), p.eabe8311-1-eabe8311-8
• Main Authors: Dresselhaus-Marais, Leora E., Winther, Grethe, Howard, Marylesa, Gonzalez, Arnulfo, Breckling, Sean R., Yildirim, Can, Cook, Philip K., Kutsal, Mustafacan, Simons, Hugh, Detlefs, Carsten, Eggert, Jon H., Poulsen, Henning Friis
• Format: Article
• Language: English
• Subjects: MATERIALS SCIENCE; Physics; SciAdv r-articles
• ISSN: 2375-2548; 2375-2548
• DOI: 10.1126/sciadv.abe8311

Dark-field X-ray microscopy movies reveal how patterns of microscopic defects in bulk aluminum destabilize from 97-99% of melting. 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 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.