Are rate sensitivity and strength effected by cross-slip in nano-twinned fcc metals

Asaro, R.J.; Kulkarni, Y.

doi:10.1016/j.scriptamat.2007.06.066

Cited by 44 publications

(20 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, in screw dislocation transmission of nt-Al, the Hall-Petch slope is 1.13 and 1.25 for the twin thickness 39 and 70 nm, respectively. This weak dependence proves the early treatment of using r a = b 1 e when maximizing the free energy of cross-slip [7,8,20]. The calculated Hall-Petch slopes for dislocation reactions are listed in Table 1.…”

Section: Evaluating Strengthening At Tbmentioning

confidence: 70%

“…In transmission, a trailing partial follows the leading partial. In absorption, when first twinning partial is activated, the second twinning partial is repealed to move in the opposite direction ϕ = −π + ϕ 1 [4,6,8]. The first twinning partial is chosen along the direction ϕ 1 because the driving force τ m′s′ b 1s′ is larger in this direction than another twinning direction ϕ 3 = −π + ϕ 1 .…”

Section: Screw Dislocationmentioning

confidence: 99%

“…In molecular dynamics (MD) simulations, various reactions of screw and non-screw dislocations in the forms of absorption to TB and/or transmission to adjacent twin lamella were discovered [4][5][6]. The role of these dislocation reactions at TB in strengthening was investigated in mechanistic model [7][8][9][10]. In recent slip transfer model [11], inter-twin flow stress, the required shear stress for absorption to TB and/or transmission to adjacent twin lamella, is quantified to be strongly dependent on twin thickness (twin density).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Strengthening at nanoscaled coherent twin boundary in f.c.c. metals

Dao

Zhu

2014

Philosophical Magazine

View full text Add to dashboard Cite

This paper analyses slip transfer at the boundary of nanoscaled growth twins in face-centred cubic (f.c.c.) metals for strengthening mechanism. The required stress for slip transfer, i.e. inter-twin flow stress, is obtained in a simple expression in terms of stacking fault energy and/or twin boundary (TB) energy, constriction energy and activation volume. For nanotwinned Al, Cu and Ni, inter-twin flow stress versus twin thickness remarkably shows Hall-Petch relationship. The Hall-Petch slope is rationalized for various reactions of screw and non-screw dislocations at the TB. Additionally, strengthening at the boundary of nanoscaled deformation twins in f.c.c. metals is analysed by evaluating required twinning stress. At small nanograin size, the prediction of deformation twin growth stress shows inverse grain-size effect on twinning, in agreement with recent experimental finding.

show abstract

Section: Evaluating Strengthening At Tbmentioning

confidence: 70%

Section: Screw Dislocationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Strengthening at nanoscaled coherent twin boundary in f.c.c. metals

Dao

Zhu

2014

Philosophical Magazine

View full text Add to dashboard Cite

show abstract

“…However, when the boundary spacing is 15-20 nm, only 2 dislocations pile up at the boundary. 37) Hence, when the boundary spacing is too narrow, for example, less than 10 nm, no pileup of dislocations occurs at the boundary and the transmission of a single dislocation plays a critical role in deformation. The experimental results in the present work demonstrate that even when the boundary spacing is less than 10 nm, the strain-rate sensitivity and activation volume depend on the boundary spacing.…”

Section: Discussionmentioning

confidence: 99%

Effect of Annealing on Mechanical Properties and Nanoscale Lamellar Structure in Co-Cu Alloy

et al. 2009

View full text Add to dashboard Cite

An electrodeposited Co-Cu alloy with a nanoscale lamellar structure was annealed at 673-973 K. The effects of annealing on the mechanical properties and the microstructures of the alloy such as the lamellar area ratio and the lamellar spacing were investigated. The Young's modulus of the Co-Cu alloy increased by annealing. This is mainly due to a decrease in the lamellar area ratio. The as-deposited specimens exhibited a low value of the activation volume for plastic deformation; however, the activation volume was increased by annealing. This appears to be related to an increase in lamellar spacing caused by annealing. The origins of the lamellar spacing dependence of the activation volume are discussed from the viewpoint of the emission of dislocations from the lamellar boundary.

show abstract

“…Nanotwinned metals have shown enhanced strength and ductility, as well as improved electrical performance, fracture toughness, and stability against cyclic loading, compared to ultrafine-grained and nanocrystalline materials. [1][2][3][4][5][6][7][8] These materials contain a high density of coherent twin boundaries (CTBs) that appear to serve as effective barriers to dislocation motion: these boundaries are the loci of changes of crystal orientation between matrix and twin, and discontinuities in most of the slip systems across the CTBs. Tensile tests of nanotwinned materials with various twin densities show that the yield strength, hardness, and ductility increase with decreasing twin spacing down to some critical spacing.…”

Section: Introductionmentioning

confidence: 99%

Effects of Schmid factor and slip nucleation on deformation mechanism in columnar-grained nanotwinned Ag and Cu

Borovikov

Mendelev

King

et al. 2015

Journal of Applied Physics

View full text Add to dashboard Cite

We report the results of a molecular dynamics study of the effect of texture on the yield and peak stresses in columnar-grained nanotwinned Ag and Cu. The simulations suggest that in pure nanotwinned face-centered cubic metals, the strength is determined primarily by the cooperation or competition between two major factors: the magnitude of the Schmid factors for the available slip systems and the effectiveness of grain boundaries (and their triple-junctions) in generating dislocations. These factors and their relative impact depend on the geometry of the specimen relative to the applied stress, which is typically reflected in the texture of the material in experimental studies. The detailed mechanisms of plastic deformation are discussed for seven specific geometries that represent a range of different textures. V C 2015 AIP Publishing LLC.

show abstract

Are rate sensitivity and strength effected by cross-slip in nano-twinned fcc metals

Cited by 44 publications

References 6 publications

Strengthening at nanoscaled coherent twin boundary in f.c.c. metals

Strengthening at nanoscaled coherent twin boundary in f.c.c. metals

Effect of Annealing on Mechanical Properties and Nanoscale Lamellar Structure in Co-Cu Alloy

Effects of Schmid factor and slip nucleation on deformation mechanism in columnar-grained nanotwinned Ag and Cu

Contact Info

Product

Resources

About