Radiation damage in helium ion irradiated nanocrystalline Fe

Kobayashi, Yu; Liu, Yue; Sun, Cheng; Wang, H.; Shao, Lin; Fu, Engang; Zhang, X.

doi:10.1016/j.jnucmat.2011.10.052

Cited by 157 publications

(102 citation statements)

References 51 publications

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“…Thus the Ostwald ripening process becomes kinetically limited as the size of the bubble grows. These results are in good agreement with the experimental work of [9] in pure Fe which show that bubbles of between 1 and 2 nm in diameter are preferentially formed at room temperature.…”

Section: Discussionsupporting

confidence: 91%

“…The size of He bubbles observed in the TEM micrograph was of the order of 0.5 nm in diameter and this small size was attributed also to the influence of Cr inhibiting bubble growth. Finally experimental work from Yu et al [9] in pure Fe at room temperature has indicated that there is a distribution of sizes with a fairly narrow spread and a preferred He bubble size of the order of 1.5 nm in diameter.…”

Section: Introductionmentioning

confidence: 96%

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Helium bubbles in bcc Fe and their interactions with irradiation

Gai

Lazauskas

Smith

et al. 2015

Journal of Nuclear Materials

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a b s t r a c tThe properties of helium bubbles in a body-centred cubic (bcc) Fe lattice have been examined. The atomic configurations and formation energies of different He-vacancy complexes were determined. The 0 K results show that the most energetically favourable He to Fe vacancy ratio increases from about 1:1 for approximately 5 vacancies up to about 4:1 for 36 vacancies. The formation mechanisms for small He clusters have also been considered. Isolated interstitials and small clusters can diffuse quickly through the lattice. MD simulations of randomly placed interstitial He atoms at 500 K showed clustering over the time scale of nanoseconds with He clusters containing up to 4 atoms being mobile over this time scale. He clusters containing 4 or 5 atoms were shown to eject an Fe dumbbell interstitial which could then detach from the He cluster and diffuse with the remaining He-vacancy complex being effectively immobile. Collision cascades initiated near larger bubbles showed that Fe vacancies produced by the cascades readily become part of the He-vacancy complexes. Energy barriers for He to join an existing bubble as a function of the He-vacancy ratio are also calculated. These can be larger than the diffusion barrier in the pristine lattice, but are lower when the bubbles contain excess vacancies, thus indicating that bubble growth may be kinetically constrained.

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Section: Discussionsupporting

confidence: 91%

Section: Introductionmentioning

confidence: 96%

Helium bubbles in bcc Fe and their interactions with irradiation

Gai

Lazauskas

Smith

et al. 2015

Journal of Nuclear Materials

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“…King and Smith 5 studied the mechanism of point defect absorption by grain boundaries and P 3 {111} coherent twin boundaries (CTBs) in electron-irradiated Al and Cu, and showed that twin boundaries may be biased sinks for dislocation loops. Recently, there are increasing interests on radiation tolerance of nanostructured materials because they possess a significant fraction of high-angle grain boundaries that lead to reduction of radiation-induced defect density 6,7 . Atomistic modelling has also been adopted to investigate the radiation response of high-angle grain boundaries in nanomaterials [8][9][10] .…”

mentioning

confidence: 99%

Removal of stacking-fault tetrahedra by twin boundaries in nanotwinned metals

et al. 2013

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Stacking-fault tetrahedra are detrimental defects in neutron-or proton-irradiated structural metals with face-centered cubic structures. Their removal is very challenging and typically requires annealing at very high temperatures, incorporation of interstitials or interaction with mobile dislocations. Here we present an alternative solution to remove stacking-fault tetrahedra discovered during room temperature, in situ Kr ion irradiation of epitaxial nanotwinned Ag with an average twin spacing of B8 nm. A large number of stacking-fault tetrahedra were removed during their interactions with abundant coherent twin boundaries. Consequently the density of stacking-fault tetrahedra in irradiated nanotwinned Ag was much lower than that in its bulk counterpart. Two fundamental interaction mechanisms were identified, and compared with predictions by molecular dynamics simulations. In situ studies also revealed a new phenomenon: radiation-induced frequent migration of coherent and incoherent twin boundaries. Potential migration mechanisms are discussed.

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“…Compared with the conventional polycrystalline materials, nanocrystalline materials exhibit the superior property of radiation resistance due to the significantly decreased grain size and the increased volume fraction of grain boundary (GB) [1,2,8,9]. It has been demonstrated that grain boundary can act as an efficient sink for reducing the accumulation of radiation defects in nanocrystalline metals [10][11][12][13], alloys [14,15], and oxides [16,17]. For example, experiments showed that grain boundary could act as a sink for both self-interstitial atoms (SIAs) and vacancies, resulting in a denuded zone in the vicinity of an interface region [18].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Mechanical Properties of Σ5(210)/[001] Tilt Grain Boundary with Self-Interstitial Atoms by Molecular Dynamics Simulation

Zhang

Lü

Pei

et al. 2017

Journal of Nanomaterials

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Grain boundary (GB) can serve as an efficient sink for radiation-induced defects, and therefore nanocrystalline materials containing a large fraction of grain boundaries have been shown to have improved radiation resistance compared with their polycrystalline counterparts. However, the mechanical properties of grain boundaries containing radiation-induced defects such as interstitials and vacancies are not well understood. In this study, we carried out molecular dynamics simulations with embedded-atom method (EAM) potential to investigate the interaction of Σ5(210)/[001] symmetric tilt GB in Cu with various amounts of self-interstitial atoms. The mechanical properties of the grain boundary were evaluated using a bicrystal model by applying shear deformation and uniaxial tension. Simulation results showed that GB migration and GB sliding were observed under shear deformation depending on the number of interstitial atoms that segregated on the boundary plane. Under uniaxial tension, the grain boundary became a weak place after absorbing self-interstitial atoms where dislocations and cracks were prone to nucleate.

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Radiation damage in helium ion irradiated nanocrystalline Fe

Cited by 157 publications

References 51 publications

Helium bubbles in bcc Fe and their interactions with irradiation

Helium bubbles in bcc Fe and their interactions with irradiation

Removal of stacking-fault tetrahedra by twin boundaries in nanotwinned metals

Evaluation of Mechanical Properties of Σ5(210)/[001] Tilt Grain Boundary with Self-Interstitial Atoms by Molecular Dynamics Simulation

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