Climb kinetics of dislocation loops in aluminium

Dobson, P. S.; Goodhew, P.J.; Smallman, R.E.

doi:10.1080/14786436708229253

Cited by 107 publications

(19 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This transition is similar to the NC case in which there was a switch from full dislocations to partial dislocations as the grain size decreased below a critical value [47][48][49][50][51]. For Ni NWs with an SF energy between $0.128 and 0.24 J/m [52,53] and a shear modulus of 93.2 GPa [46], the critical grain size ranged from $11 to 22 nm. When considering the twin thickness as the grain size, it is reasonable that only partial dislocations were observed when the TT was less than 6.5 nm.…”

Section: Discussionmentioning

confidence: 63%

Dynamic and atomic-scale understanding of the twin thickness effect on dislocation nucleation and propagation activities by in situ bending of Ni nanowires

et al. 2015

View full text Add to dashboard Cite

Although their mechanical behavior has been extensively studied, the atomic-scale deformation mechanisms of metallic nanowires (NWs) with growth twins are not completely understood. Using our own atomic-scale and dynamic mechanical testing techniques, bending experiments were conducted on single-crystalline and twin-structural Ni NWs (D = $40 nm) using a high-resolution transmission electron microscope (HRTEM). Atomic-scale and time-resolved dislocation nucleation and propagation activities were captured in situ. A large number of in situ HRTEM observations indicated strong effects from the twin thickness (TT) on dislocation type and glide system. In thick twin lamella (TT > $12 nm) and single-crystalline NWs, the plasticity was controlled by full dislocation nucleation. For NWs with twin thicknesses of $9 nm < TT < $12 nm, full and partial dislocation nucleation occurred from the free surface, and the dislocations glided on multiple systems and interacted with each other during plastic deformation. For NWs with twin thicknesses of $6 nm < TT < $9 nm, partial dislocation nucleation from the free surface and the gliding of those dislocations on the plane that intersected the twin boundaries (TBs) were the dominant plasticity events. For the NWs with twin thicknesses of $1 nm < TT < $6 nm, the plasticity was accommodated by a partial dislocation nucleation process and glide parallel to the TBs. When TT < $1 nm, TB migration and detwinning processes resulting from partial dislocation nucleation and glide adjacent to the TBs were frequently observed.

show abstract

Section: Discussionmentioning

confidence: 63%

Dynamic and atomic-scale understanding of the twin thickness effect on dislocation nucleation and propagation activities by in situ bending of Ni nanowires

et al. 2015

View full text Add to dashboard Cite

show abstract

“…35,36 In these experiments, the chemical stress remains close to zero because the surfaces are efficient sinks for vacancies. The driving mechanical force iŝ T R zc, whereT is the dislocation line tension, R is the average loop radius, and c is the stacking fault energy.…”

Section: Comparison With Experimental Resultsmentioning

confidence: 81%

Dislocation motion controlled by interactions with crystal lattice: modelling and experiments

Caillard¹,

Martin²

2005

International Materials Reviews

View full text Add to dashboard Cite

In an attempt to establish a correct physical description of the mechanical behaviour of a crystal, the present paper presents first a critical review of two dislocation mobility processes: glide in covalent crystals, and pure climb at high temperatures. Models are presented together with experimental data to test them. The study then gathers available information about the way dislocations multiply, are held up in the substructure and the resultant work hardening of the crystal.

show abstract

“…The fact that double layer loops form at all suggests that the energy of the resulting extrinsic fault is less than twice the intrinsic fault energy. This has been confirmed by comparative annealing experiments on faulted and unfaulted loops in aluminium (Dobson and Smallman 1966) which show that the intrinsic fault energy is about 130 erg cm-2 while the extrinsic fault energy is about 170 erg cm-' (Dobson et al 1967, Kritzinger er a1 1969.…”

Section: Aluminiummentioning

confidence: 77%

“…Considering first the results from dislocation loops, most of the shrinkage experiments have been directed towards a determination of stacking fault energies following the early experiments by Edington and Smallman (1 965). It has been shown that the shrinkage of dislocation loops in aluminium foils is diffusion controlled (Dobson et al 1967). For large loops (loop radius r greater than half the foil thickness) it is appropriate to solve the diffusion equations for cylindrical symmetry and the rate of shrinkage for extrinsically faulted (drldt),, and perfect loops (dr/dtb are given by Dobson and Smallman (1966) and…”

Section: Measurement Of Self Diffusion Parametersmentioning

confidence: 99%

Self-wave processes in a wide-aperture laser with an additional nonlinear component

Zaikin

1996

Quantum Electron.

View full text Add to dashboard Cite

The paper reviews the contribution that transmission electron microscopy has made to our understanding of the mobility and clustering of point defects in fcc and bcc metals. The first part of the paper considers the nucleation and growth of vacancy clusters in quenched fcc metals. Most of the results have been obtained for gold and aluminium and a good understanding has been achieved of the factors governing the type of defects that are nucleated in these metals. In the second part of the paper the complex subject of irradiation damage is discussed with emphasis being placed on showing the inter-relationship existing between basic damage processes governing defect production and the visible defect structure. A selfconsistent picture is now emerging of the damage structures produced by irradiation at low temperatures which provides a basis for understanding the sometimes very varied results obtained in different experiments. The third section of the paper discusses the observation of cluster growth and shrinkage in terms of the information they provide about defect mobility. In the final part of the paper a summary is presented of the main conclusions that can be drawn from electron microscope studies regarding the behaviour of vacancy and interstitial defects in fcc and bcc metals.

show abstract

Climb kinetics of dislocation loops in aluminium

Cited by 107 publications

References 13 publications

Dynamic and atomic-scale understanding of the twin thickness effect on dislocation nucleation and propagation activities by in situ bending of Ni nanowires

Dynamic and atomic-scale understanding of the twin thickness effect on dislocation nucleation and propagation activities by in situ bending of Ni nanowires

Dislocation motion controlled by interactions with crystal lattice: modelling and experiments

Self-wave processes in a wide-aperture laser with an additional nonlinear component

Contact Info

Product

Resources

About