Discrete shear band plasticity through dislocation activities in body-centered cubic tungsten nanowires
- Zhejiang Univ., Hangzhou (China).
- Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Stanford Univ., CA (United States)
- Stanford Univ., CA (United States)
- Univ. of Pittsburgh, PA (United States)
Shear band in metallic crystals is localized deformation with high dislocation density, which is often observed in nanopillar deformation experiments. The shear band dynamics coupled with dislocation activities, however, remains unclear. Here, we investigate the dynamic processes of dislocation and shear band in body-centered cubic (BCC) tungsten nanowires via an integrated approach of in situ nanomechanical testing and atomistic simulation. We find a strong effect of surface orientation on dislocation nucleation in tungsten nanowires, in which {111} surfaces act as favorite sites under high strain. While dislocation activities in a localized region give rise to an initially thin shear band, self-catalyzed stress concentration and dislocation nucleation at shear band interfaces cause a discrete thickening of shear band. Our findings not only advance the current understanding of defect activities and deformation morphology of BCC nanowires, but also shed light on the deformation dynamics in other microscopic crystals where jerky motion of deformation band is observed.
- Research Organization:
- Stanford Univ., CA (United States)
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- SC0010412
- OSTI ID:
- 1500035
- Journal Information:
- Scientific Reports, Vol. 8, Issue 1; ISSN 2045-2322
- Publisher:
- Nature Publishing GroupCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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