The measurement of stacking-fault energies of pure face-centred cubic metals

Cockayne, D. J. H.; Jenkins, M. L.; Ray, I.L.F.

doi:10.1080/14786437108217419

Cited by 299 publications

(66 citation statements)

References 14 publications

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“…As expected, the edge component of the density is zero at the cross-slip plane because only the screw displacement can cross-slip. On the other hand, the screw dislocation in Ag dissociates into two partials, separated by 7.8 b (≈ 22Å), in excellent agreement with the experimental value of 20Å in TEM measurements [17]. The left (right) partial has a positive (negative) edge component of the Burgers vector represented by the positive (negative) density.…”

Section: I(ii)supporting

confidence: 72%

A nonplanar Peierls–Nabarro model and its application to dislocation cross-slip

Lü

Bulatov

Kioussis

2003

Philosophical Magazine

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A novel semidiscrete Peierls-Nabarro model is introduced which can be used to study dislocation spreading at more than one slip planes, such as dislocation cross-slip and junctions. The strength of the model, when combined with ab initio calculations for the energetics, is that it produces essentially an atomistic simulation for dislocation core properties without suffering from the uncertainties associated with empirical potentials. Therefore, this method is particularly useful in providing insight into alloy design when empirical potentials are not available or not reliable for such multi-element systems. As an example, we study dislocation cross-slip and constriction process in two contrasting fcc metals, Al and Ag. We find that the screw dislocation in Al can cross-slip spontaneously in contrast with that in Ag, where the screw dislocation splits into two partials, which cannot cross-slip without first being constricted. The response of the dislocation to an external stress is examined in detail. The dislocation constriction energy and the critical stress for cross-slip are determined, and from the latter, we estimate the cross-slip energy barrier for straight screw dislocations.

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Section: I(ii)supporting

confidence: 72%

A nonplanar Peierls–Nabarro model and its application to dislocation cross-slip

Lü

Bulatov

Kioussis

2003

Philosophical Magazine

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“…Whilst the SFE's of silver and CulO%Al ace similar [8], dislocations in the two materials respond differently to irradiation: Under room-tcmpcraturc electron irradiation, dislocations in silver generally seem to constrict and promote in their vicinity the formation of dislocation loops ami (especially) stacking-fault tetrahedra (SFT) [9]. There was no indication of major climb motion nor of complex interactions between the clusters and line dislocations.…”

Section: A Silvermentioning

confidence: 93%

The Interaction of HVEM-Generated Point-Defects with Dissociated Dislocations

King¹,

Jenkins²,

Kirk³

et al. 1992

MSF

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This paper describes experiments we have performed to investigate the mechanisms of interaction of IIVEM-gcncralcd point-defects with dissociated dislocations in a scries of austcniticFc-Ni-Cr alloys and reviews earlier work in Cu-AI alloys and in Ag. In the Fc-Ni-Cr alloys interstitial climb was observed only at favourable sites such as pre-existing jogs, whilst vacancies clustered near dislocations to form stacking-fault tetrahedra. These observations arc similar to these in Ag; the complex climb mechanisms seen in Cu-AI alloys were not found. The differences bet ween materials is believed to be due to differences in the case of interstitial pipe diffusion. INTRODUCTIONThe interaction of radiation-produced point defects witli dislocations is central to the understanding of phenomena which give rise to dimensional or mechanical-property changes in nuclear reactors. As part of a more general effort to understand microslructural evolution under irradiation, studies of the mechanisms of interaction of IIVEM-gcncralcd point-defects with dissociated dislocations have been carried out in Oxford, Harwell and Argonnc over the past 11 years. Various model materials have been chosen, starling with very low slacking-faull energy (SFE) CuAl alloys with wide partial separations and progressing towards the structural steels of practical importance. These studies have demonstrated that dislocation climb in these materials may be far from straightforward. In this paper we briefly review early studies in CuAl alloys and in Ag and present some of our more recent results in Fc-Ni-Cr alloys, The observations in the different materials will be compared and contrasted and possible origins for differences and similarities between materials will be discussed.

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“…Over the years, defining the relationships between core properties and material parameters that apply to a wide range of material properties has been difficult. Experimental equilibrium stacking fault widths exhibit large variations owing to dislocation line curvature, orientation and nearby unknown internal stress fields [18][19][20]. The classical model from dislocation theory for stacking fault widths does not consistently fit the experimental data for all metals [9,21].…”

Section: Extended Dislocationsmentioning

confidence: 98%

“…If the trailing partial does not emit and predominantly leading partials accommodate slip in the grain, then the crystal is said to deform alternatively by partial-mediated slip. Whether partial-mediated slip or conventional slip operates greatly affects the propensity for basic deformation mechanisms, such as twinning, crossslip, dislocation storage (strain hardening) and GB mobility (grain growth) [18,20,[26][27][28].…”

Section: Intragranular Dislocation Mechanicsmentioning

confidence: 99%

Understanding dislocation mechanics at the mesoscale using phase field dislocation dynamics

Beyerlein

Hunter

2016

Phil. Trans. R. Soc. A.

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One contribution of 11 to a theme issue 'Trends and challenges in the mechanics of complex materials' . In this paper, we discuss the formulation, recent developments and findings obtained from a mesoscale mechanics technique called phase field dislocation dynamics (PFDD). We begin by presenting recent advancements made in modelling face-centred cubic materials, such as integration with atomic-scale simulations to account for partial dislocations. We discuss calculations that help in understanding grain size effects on transitions from full to partial dislocation-mediated slip behaviour and deformation twinning. Finally, we present recent extensions of the PFDD framework to alternative crystal structures, such as body-centred cubic metals, and two-phase materials, including free surfaces, voids and bi-metallic crystals. With several examples we demonstrate that the PFDD model is a powerful and versatile method that can bridge the length and time scales between atomistic and continuum-scale methods, providing a much needed understanding of deformation mechanisms in the mesoscale regime.

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The measurement of stacking-fault energies of pure face-centred cubic metals

Cited by 299 publications

References 14 publications

A nonplanar Peierls–Nabarro model and its application to dislocation cross-slip

A nonplanar Peierls–Nabarro model and its application to dislocation cross-slip

The Interaction of HVEM-Generated Point-Defects with Dissociated Dislocations

Understanding dislocation mechanics at the mesoscale using phase field dislocation dynamics

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