Twin boundary spacing-dependent deformation behaviours of twinned silver nanowires

Abstract

Twin boundary spacing (TBS) plays a significant role in the yield behaviour of twinned nanowires (NWs). However, few studies have shown an overall view of the effects on the mechanical response of twinned silver NWs under tensile loading. In this article, the mechanical properties of 〈111〉-oriented NWs with different TBSs are studied using molecular dynamics simulations. In elastic region, it is found that the addition of twin boundaries (TBs) to crystalline NWs can not only cause strengthening but also softening effect, which depending on the S_T/S_F (the ratio of the total area of TBs to the area of lateral free surfaces). Furthermore, our simulation results show that the evolution of reduced number of different types of atoms in twinned Ag NWs has a strong dependence on TBS. For twinned NWs with larger TBSs, the dislocation–TB interaction dominates the plastic deformation process. While for twinned NWs with smaller TBSs, shear banding is activated as the incipient plastic deformation, leading to the atoms clustering into disorder near the surfaces. The study will be helpful to the further understanding of TB-related mechanical properties of nanomaterials.

Keywords::

• twin boundary spacing
• tension
• silver nanowires
• molecular dynamics

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (NSFC) [grant number 20873063], [grant number and 51071084], the National Basic Research Program of China (973 Program), [grant number 2007CB936302], [grant number 2010CB732400], the Natural Science Foundation of Jiangsu Province [grant number BK2010389] and the Fundamental Research Funds for the Central Universities.