Molecular dynamics simulation of tensile deformation mechanisms in nanocrystalline TWIP steel

verfasst von
Ranran Zhang, Brahmanandam Javvaji, Haifei Zhan, Min Xia, Manchao He, Xiaolong Fu, Xiaoying Zhuang
Abstract

We perform tensile deformation studies on nanocrystalline twinning-induced plasticity (TWIP) steels using molecular dynamics (MD) simulations and observe significant volume changes during incremental deformation. The meta-atomic potential function is employed to define atomic interactions in TWIP steels. The nucleation and propagation of dislocations lead to a reduction in tensile stress, which is positively correlated with the average grain size. Tensile tests show that TWIP steels undergo a phase transformation during plastic deformation, primarily from the face-centred cubic (FCC) to the HCP phase. This transformation results in the formation of stacking faults (SFs) and twin boundaries (TBs). The slip of dislocations is intercepted by grain boundaries (GBs) and TBs, leading to stress concentration. When the stress reaches a critical threshold, cracks initiate and propagate at these weak points, causing volume expansion during plastic deformation. This volume change results from the interaction between the material's complex microstructure and the generation and progression of cracks. In contrast, nanocrystalline Cu exhibits nearly constant volume during the plastic deformation stage, attributed to the insufficient dislocation slip and phase transformations in Cu. Overall, the observed volume increase is specific to TWIP steels and contributes to their high ductility.

Organisationseinheit(en)
Institut für Photonik
Externe Organisation(en)
Zhejiang University (ZJU)
University of Science and Technology Beijing
Tongji University
Xi'an Modern Chemistry Research Institute
Typ
Artikel
Journal
Journal of Micromechanics and Molecular Physics
Band
10
Seiten
1-10
Anzahl der Seiten
10
ISSN
2424-9130
Publikationsdatum
10.03.2025
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Keramische und Verbundwerkstoffe, Atom- und Molekularphysik sowie Optik, Werkstoffmechanik, Polymere und Kunststoffe
Elektronische Version(en)
https://doi.org/10.1142/S2424913025500018 (Zugang: Geschlossen)
 

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