Orientation dependent deformation behaviour of BCC iron nanowires

Sainath, G.; Choudhary, B.K.

doi:10.1016/j.commatsci.2015.09.055

Cited by 119 publications

(76 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…6 and 7 . Under tensile loading, BCC Fe nanowires oriented in <100>, <112> and <102> axial directions deform predominantly by the twinning mechanism, whereas the full dislocation slip has been observed in <110> and <111> orientations 8 . Further, it has been shown that BCC Fe nanowires exhibit tension-compression asymmetry in deformation mechanisms 8,9 .…”

Section: Introductionmentioning

confidence: 99%

“…Under tensile loading, BCC Fe nanowires oriented in <100>, <112> and <102> axial directions deform predominantly by the twinning mechanism, whereas the full dislocation slip has been observed in <110> and <111> orientations 8 . Further, it has been shown that BCC Fe nanowires exhibit tension-compression asymmetry in deformation mechanisms 8,9 . In contrast to tensile loading, the nanowire with <100> orientation deformed by the dislocation slip, whereas twinning was observed in <110> orientation under compressive loading [8][9][10] .…”

Section: Introductionmentioning

confidence: 99%

“…Further, it has been shown that BCC Fe nanowires exhibit tension-compression asymmetry in deformation mechanisms 8,9 . In contrast to tensile loading, the nanowire with <100> orientation deformed by the dislocation slip, whereas twinning was observed in <110> orientation under compressive loading [8][9][10] . Recently, Wang et al 11 have provided the first experimental evidence of deformation twinning in BCC W nanowires with 15 nm diameter thereby conforming the predictions made using MD simulations.…”

Section: Introductionmentioning

confidence: 99%

“…Most of these studies in BCC metallic nanowires have been focused mainly on deformation aspects such as twinning and dislocation behavior [8][9][10][11][12][13][14][15][16][17][18][19][20] . It is surprising that enough attention has not been paid towards the fracture behavior of BCC Fe nanowires.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Atomistic simulations on ductile-brittle transition in ⟨111⟩ BCC Fe nanowires

Sainath

Choudhary

2017

Journal of Applied Physics

Self Cite

View full text Add to dashboard Cite

Molecular dynamics simulations have been performed to understand the influence of temperature on the tensile deformation and fracture behavior of <111> BCC Fe nanowires. The simulations have been carried out at different temperatures in the range 10-1000 K employing a constant strain rate of 1× 10 8 s −1 . The results indicate that at low temperatures (10-375 K), the nanowires yield through the nucleation of a sharp crack and fails in brittle manner. On the other hand, nucleation of multiple 1/2<111> dislocations at yielding followed by significant plastic deformation leading to ductile failure has been observed at high temperatures in the range 450-1000 K. At the intermediate temperature of 400 K, the nanowire yields through nucleation of crack associated with many mobile 1/2<111> and immobile <100> dislocations at the crack tip and fails in ductile manner. The ductile-brittle transition observed in <111> BCC Fe nanowires is appropriately reflected in the stress-strain behavior and plastic strain at failure. The ductile-brittle transition increases with increasing nanowire size. The change in fracture behavior has been discussed in terms of the relative variations in yield and fracture stresses and change in slip behavior with respect to temperature. Further, the dislocation multiplication mechanism assisted by the kink nucleation from the nanowire surface observed at high temperatures has been presented.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Atomistic simulations on ductile-brittle transition in ⟨111⟩ BCC Fe nanowires

Sainath

Choudhary

2017

Journal of Applied Physics

Self Cite

View full text Add to dashboard Cite

show abstract

“…In a recent comprehensive molecular dynamics (MD) study by Sainath et al, the mechanical deformation properties and related atomistic mechanisms of metallic Fe nanowires were investigated as a function of various experimental conditions by using embedded-atom method (EAM) interatomic potentials. 6,26,27 In their first study, 26 the authors indicated that the deformation mode was dependent on the loading direction for h110i/{111}-orientated metallic Fe NWs. Mainly, two different deformation mechanisms were observed: twinning in tension and full dislocation slip in compressive loading.…”

Section: Introductionmentioning

confidence: 99%

Effects of oxidation on tensile deformation of iron nanowires: Insights from reactive molecular dynamics simulations

Aral

Wang

Ogata

et al. 2016

Journal of Applied Physics

View full text Add to dashboard Cite

The influence of oxidation on the mechanical properties of nanostructured metals is rarely explored and remains poorly understood. To address this knowledge gap, in this work, we systematically investigate the mechanical properties and changes in the metallic iron (Fe) nanowires (NWs) under various atmospheric conditions of ambient dry O 2 and in a vacuum. More specifically, we focus on the effect of oxide shell layer thickness over Fe NW surfaces at room temperature. We use molecular dynamics (MD) simulations with the variable charge ReaxFF force field potential model that dynamically handles charge variation among atoms as well as breaking and forming of the chemical bonds associated with the oxidation reaction. The ReaxFF potential model allows us to study large length scale mechanical atomistic deformation processes under the tensile strain deformation process, coupled with quantum mechanically accurate descriptions of chemical reactions. To study the influence of an oxide layer, three oxide shell layer thicknesses of $4.81 Å , $5.33 Å , and $6.57 Å are formed on the pure Fe NW free surfaces. It is observed that the increase in the oxide layer thickness on the Fe NW surface reduces both the yield stress and the critical strain. We further note that the tensile mechanical deformation behaviors of Fe NWs are dependent on the presence of surface oxidation, which lowers the onset of plastic deformation. Our MD simulations show that twinning is of significant importance in the mechanical behavior of the pure and oxide-coated Fe NWs; however, twin nucleation occurs at a lower strain level when Fe NWs are coated with thicker oxide layers. The increase in the oxide shell layer thickness also reduces the external stress required to initiate plastic deformation. Published by AIP Publishing.

show abstract

The Formation and Evolution of Defects in Nanocrystalline Fe During Indentation: The Role of Twins in Pop‐Ins

Kuhr

Aifantis

2018

Physica Status Solidi (b)

View full text Add to dashboard Cite

Nanoindentation is a most common experimental tool used for obtaining information on the mechanical behavior of materials. This is done by qualitatively relating the occurrence of pop‐ins (in the load–displacement plots) to microstructural changes such as dislocation formation, fracture of surface oxides, or slip transmission. The present study takes a first approach in directly verifying the micro‐plasticity processes that give rise to such pop‐ins by performing molecular dynamics indentation simulations in BCC Fe‐nanocrystals with a Σ5 symmetric tilt boundary. The simulations allow to track the material behavior throughout the indentation process, and illustrate that each pop‐in is related to twin formation, twin growth, de‐twinning, dislocation nucleation and glide, or dislocation–grain boundary interactions. For the particular Σ5 boundary considered, it is found that the pop‐ins are most closely associated with twin formation. Although pop‐ins have been related to dislocation nucleation, a direct correlation between twinning and pop‐ins has not been shown before. Adding C segregants to the Fe sample, reduced the formation of twins after initial yielding, and allowed for dislocation activity to become the more dominant deformation mechanism.

show abstract

Orientation dependent deformation behaviour of BCC iron nanowires

Cited by 119 publications

References 33 publications

Atomistic simulations on ductile-brittle transition in ⟨111⟩ BCC Fe nanowires

Atomistic simulations on ductile-brittle transition in ⟨111⟩ BCC Fe nanowires

Effects of oxidation on tensile deformation of iron nanowires: Insights from reactive molecular dynamics simulations

The Formation and Evolution of Defects in Nanocrystalline Fe During Indentation: The Role of Twins in Pop‐Ins

Contact Info

Product

Resources

About