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arXiv · 2507.00759

Decomposition of general grain boundaries

Wei Wan·Junwen Deng·Changxin Tang
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Abstract

As a central part of microstructure evolution, grain boundary (GB) migration is believed to be both monolithic and unidirectional. But here, we introduce the concept of GB decomposition: one GB separates into two new GBs by exerting differential Peach-Koehler forces on its disconnections. Molecular dynamics simulation is used to reveal the disconnection mechanisms and direction-dependent motion behaviors associated with the reversible decomposition of a nickel {\Sigma}7 general GB. We also observed a decomposition-like process in a high-energy diffraction microscopy (HEDM) dataset of high purity nickel polycrystal (Science 2021, 374, 189-193), and performed HEDM-data-based simulations to confirm it. The decomposition should be considered as a new GB kinetic behavior, based on its particularity and potential universality.

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Wei Wan, Junwen Deng, Changxin Tang. 2025-07-01. Decomposition of general grain boundaries. https://arxiv.org/abs/2507.00759

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