The deformation behaviour of silver nanowires with kinked twin boundaries under tensile loading

ABSTRACT

Atomistic simulations are used to investigate the mechanical properties of silver nanowires (NWs) with kinked twin boundaries (TBs) under tensile loading. For comparison, a different ledge width of twinned NWs with both square and circular kink-steps are considered in this study. The embedded-atom-method potential is employed to describe the atomic interactions. To identify the defect evolution and incipient plastic deformation mechanism, the centrosymmetry parameter is implemented in our self-developed programme. Twinned NWs with both square and circular ledges are shown to have a reduced impact on yield stress as compared to their perfect TBs counterpart models in elastic deformation. In twinned NWs with rectangular ledges, a strain-hardening effect was observed in defective NWs. The incipient plastic deformation is influenced by the ledge width. While in twinned NWs with circular ledges, the ledges rather than the surface effect are the only dislocation source in their incipient plastic deformation. Our findings offer a view of imperfection in twinned NWs, and it is believed that the attention being paid to defective TBs will be helpful to further understanding of the mechanical properties of TB-strengthened NWs.

KEYWORDS:

• Molecular dynamic simulation
• nanowires
• twin boundary
• defective twins

Acknowledgements

Much thanks to The Testing Center of Yangzhou University due to all the characterisations.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The funding of this work was provided by National Natural Science Foundation of China [grant number 31371806]; University Natural Science Foundation of Jiangsu Province [grant number 15KJA550004], Priority Academic Program Development of Jiangsu Higher Education Institution (PAPD).