Modeling the impact of twin boundaries on the deformation of nanotwinned metals: A dislocation dynamics approach
Wei DA, Zaiser M, Tang J, Zhang X (2026)
Publication Type: Journal article
Publication year: 2026
Journal
Book Volume: 320
Article Number: 122696
DOI: 10.1016/j.actamat.2026.122696
Abstract
The impact of twin boundaries (TBs) on the microstructure evolution and plastic deformation mechanisms of face-centered cubic (FCC) metals has been extensively studied since the discovery that nanotwinned materials exhibit a favorable combination of high strength and ductility. In this work, a dislocation-twin boundary interaction model for copper is incorporated into a three-dimensional discrete dislocation dynamics (DDD) framework. This approach is applied to systematically investigate the orientation effects on the deformation of nanotwinned copper, utilizing a multilayer twinned structure (MTS) with a twin thickness of 160 nm. The simulation results show that the stress–strain response of MTSs under uniaxial loading depends significantly on the orientation of the loading axis. When the loading axis is perpendicular or parallel to TBs, geometric confinement constrains dislocations to slip within single- or multi-layer twin lamellae on glide planes inclined to the TBs. When the loading axis is inclined to the TBs, in contrast, the highest resolved shear stress acts on glide planes parallel to the TBs, preferentially activating twinning dislocations. These dislocations glide unimpeded, which defines the soft deformation mode. If the hard mode dominates the deformation mechanism, microstructures with a single-layer confined slip lead to significant hardening behavior, while microstructures with multilayer confined slip maintain stable plastic flow and do not lead to hardening. Finally, by incorporating dislocation-mode-specific critical resolved shear stresses — physically motivated thresholds reflecting the distinct resistance of hard mode Ⅰ, hard mode Ⅱ, and soft-mode dislocation–TB interactions — we extend Schmid’s law to predict the orientation-dependent yield stress of MTSs.
Authors with CRIS profile
Involved external institutions
Southwest Jiaotong University / 西南交通大学
China (CN)
Institute of Mechanics (Chinese Academy of Sciences) / 力学研究所
China (CN)
China (CN)
Institute of Mechanics (Chinese Academy of Sciences) / 力学研究所
China (CN)
How to cite
APA:
Wei, D.A., Zaiser, M., Tang, J., & Zhang, X. (2026). Modeling the impact of twin boundaries on the deformation of nanotwinned metals: A dislocation dynamics approach. Acta Materialia, 320. https://doi.org/10.1016/j.actamat.2026.122696
MLA:
Wei, De An, et al. "Modeling the impact of twin boundaries on the deformation of nanotwinned metals: A dislocation dynamics approach." Acta Materialia 320 (2026).
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