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arXiv · 2411.10350

Secondary Grain Boundary Dislocations Alter Segregation Energy Spectra

Xinren Chen·William Gonçalves·Yi Hu·Yipeng Gao·Patrick Harrison·Saurabh Mohan Das·Gerhard Dehm·Baptiste Gault·Wolfgang Ludwig·Edgar Rauch·Xuyang Zhou·Dierk Raabe
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Abstract

Grain boundaries (GBs) trigger structure-specific chemical segregation of solute atoms. According to the three-dimensional (3D) topology of grains, GBs - although defined as planar defects - cannot be free of curvature. This implies formation of topologically-necessary arrays of secondary GB dislocations. We report here that these pattern-forming secondary GB dislocations can have an additional and, in some cases, even a much stronger effect on GB segregation than defect-free GBs. Using nanoscale correlative tomography combining crystallography and chemical analysis, we quantified the relationship between secondary GB dislocations and their segregation energy spectra for a model Fe-W alloy. This discovery unlocks new design opportunities for advanced materials, leveraging the additional degrees of freedom provided by topologically-necessary secondary GB dislocations to modulate segregation.

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Xinren Chen, William Gonçalves, Yi Hu, Yipeng Gao, Patrick Harrison, Saurabh Mohan Das, Gerhard Dehm, Baptiste Gault, Wolfgang Ludwig, Edgar Rauch, Xuyang Zhou, Dierk Raabe. 2024-11-15. Secondary Grain Boundary Dislocations Alter Segregation Energy Spectra. https://arxiv.org/abs/2411.10350

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