Deformation behaviour of body centered cubic Fe nanowires under tensile and compressive loading

TL;DR

This study uses molecular dynamics simulations to explore how body-centered cubic Fe nanowires deform differently under tension and compression, revealing distinct mechanisms like dislocation slip and twinning.

Contribution

It provides new insights into the asymmetric deformation mechanisms of BCC Fe nanowires under different loading conditions using atomistic simulations.

Findings

Tensile deformation involves slip of full dislocations.

Compressive deformation is dominated by twinning.

Deformation mechanisms differ significantly between tension and compression.

Abstract

Molecular Dynamics (MD) simulations have been carried out to investigate the deformation behaviour of <110>/{111} body centered cubic (BCC) Fe nanowires under tensile and compressive loading. An embedded atom method (EAM) potential was used to describe the interatomic interactions. The simulations were carried out at 10 K with a constant strain rate of $1\times10^{8}$ $s^{-1}$. The results indicate a significant differences in deformation mechanisms under tensile and compressive loading. Under tensile loading, the deformation occurs by the slip of full dislocations, While under compressive loading twinning was observed as the dominant mode of deformation. The tension-compression asymmetry in deformation mechanisms of BCC Fe nanowires is attributed to twinning-antitwinning asymmetry of 1/6<111> partial dislocation on {112} planes. We further explain the mechanism of dislocation pile up in tensile loading and twin growth in compressive loading.