Stability and mobility of defect clusters and dislocation loops in metals

Osetsky, Yu.N.; Bacon, D. J.; Serra, A.; Singh, B.N.; Golubov, S.I.

doi:10.1016/s0022-3115(99)00170-1

Cited by 276 publications

(157 citation statements)

References 46 publications

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“…For example, under high-energy ion or neutron irradiation conditions, self-interstitial atom (SIA) clusters are produced by atomic collisions in the crystal. They can be represented as rigid small prismatic dislocation loops that can migrate randomly in the drift field of dislocations (Osetsky et al 2000). The results of KMC simulations shown in figure 5 , illustrate the stages of SIA motion and clustering in the stress field of dislocations.…”

Section: The Kinetic Monte Carlo Methodsmentioning

confidence: 98%

Multiscale modelling of nanomechanics and micromechanics: an overview

Ghoniem

Busso

Kioussis

et al. 2003

Philosophical Magazine

138

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Recent advances in analytical and computational modelling frameworks to describe the mechanics of materials on scales ranging from the atomistic, through the microstructure or transitional, and up to the continuum are reviewed. It is shown that multiscale modelling of materials approaches relies on a systematic reduction in the degrees of freedom on the natural length scales that can be identified in the material. Connections between such scales are currently achieved either by a parametrization or by a 'zoom-out' or 'coarse-graining' procedure. Issues related to the links between the atomistic scale, nanoscale, microscale and macroscale are discussed, and the parameters required for the information to be transferred between one scale and an upper scale are identified. It is also shown that seamless coupling between length scales has not yet been achieved as a result of two main challenges: firstly, the computational complexity of seamlessly coupled simulations via the coarse-graining approach and, secondly, the inherent difficulty in dealing with system evolution stemming from time scaling, which does not permit coarse graining over temporal events. Starting from the Born-Oppenheimer adiabatic approximation, the problem of solving quantum mechanics equations of motion is first reviewed, with successful applications in the mechanics of nanosystems. Atomic simulation methods (e.g. molecular dynamics, Langevin dynamics and the kinetic Monte Carlo method) and their applications at the nanoscale are then discussed. The role played by dislocation dynamics and statistical mechanics methods in understanding microstructure self-organization, heterogeneous plastic deformation, material instabilities and failure phenomena is also discussed.

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Section: The Kinetic Monte Carlo Methodsmentioning

confidence: 98%

Multiscale modelling of nanomechanics and micromechanics: an overview

Ghoniem

Busso

Kioussis

et al. 2003

Philosophical Magazine

138

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“…Experimental observations [34][35][36][37] and atomistic simulation studies 38,39 have been studied using MD and experiments. 42,43 In this work, we developed a phase-field model to study the stability and growth kinetics of an interstitial loop with…”

Section: Part I: Phase-field Model For Interstitial Loop Evolution Kimentioning

confidence: 99%

Phase-field Model for Interstitial Loop Growth Kinetics and Thermodynamic and Kinetic Models of Irradiated Fe-Cr Alloys

Li¹,

Hu²,

Sun³

et al. 2011

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“…29 They then shrink due to vacancy absorption, and below a minimum size n i0 of 4-5 interstitials they become mobile in a way similar to single interstitials. 30,31 Since the majority of interstitial clusters have, at the moment of creation, a size n ig Ϸ 6 -10 atoms, 32 ␣ Ϸ 1. On the other hand, vacancy loops are assumed to have bigger size at the point of creation ͑n vg Ϸ 30-50͒, and the corresponding value of ␣ in ͑1͒ is negligible.…”

Section: Kinetic Modelmentioning

confidence: 99%

“…However, they are randomly distributed and do not participate in the ordering. 12,13 In this regard, it is worth noting that the onedimensional migration of small self-interstitial clusters, which is observed in molecular dynamic simulations, 31 and often used to explain void-lattice formation, 36,37 takes place along the closed-packed directions, i.e., ͗110͘ in fcc metals. At the same time, it is shown in Ref.…”

Section: ͑35͒mentioning

confidence: 99%

Spatial ordering of primary defects at elevated temperatures

Семенов

Woo

2005

Phys. Rev. B

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We consider the microstructure evolution of a nonequilibrium system of primary defects, in which mobile point defects, vacancy loops, and sessile interstitial clusters are continuously produced by cascade-damage irradiation. It is shown that in a fully annealed metal, a spatially homogeneous microstructure may become unstable if the yield of vacancy clusters in collision cascades is sufficiently low. Unlike cases studied in the literature, in which sessile interstitial clusters are not produced, we found that the instability condition can only be satisfied for a finite period of time, the duration of which depends on the density of the network dislocation. Spatial heterogeneity starts to form from a homogeneous vacancy loop population, leading to the eventual accumulation of almost all vacancy clusters within very sharp walls. The spatial distribution of interstitial clusters, on the other hand, is relatively homogeneous, simply following the spatial variations of the net interstitial flux. The spatial heterogeneity develops with the growth of some concentration peaks and the disappearance of others. As a result, the surviving peaks form an increasingly well-defined periodic structure. Nevertheless, as the total sink density of interstitial clusters and loops becomes sufficiently large, the periodic structure disappears, and spatial homogeneity of damage microstructure eventually returns.

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Stability and mobility of defect clusters and dislocation loops in metals

Cited by 276 publications

References 46 publications

Multiscale modelling of nanomechanics and micromechanics: an overview

Multiscale modelling of nanomechanics and micromechanics: an overview

Phase-field Model for Interstitial Loop Growth Kinetics and Thermodynamic and Kinetic Models of Irradiated Fe-Cr Alloys

Spatial ordering of primary defects at elevated temperatures

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