Effects of edge dislocations on interstitial helium and helium cluster behavior in α-Fe

Wang, Y.X.; Xu, Qiu; Yoshiie, T.; Pan, Zhiyong

doi:10.1016/j.jnucmat.2008.02.066

Cited by 41 publications

(15 citation statements)

References 26 publications

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“…Other studies have examined vacancy-dislocation interactions in dislocation climb processes in iron 98 . Additionally, there have been multiple studies that have investigated the energetics of interaction of vacancies, interstitials, and He with dislocations [99][100][101][102][103][104] . Interestingly, these studies of lattice dislocation and defect interactions can also be interpretted in terms of low angle grain boundary behavior as well.…”

Section: A Examining the Structures And Energies Of Symmetric Tilt Gmentioning

confidence: 99%

Probing grain boundary sink strength at the nanoscale: Energetics and length scales of vacancy and interstitial absorption by grain boundaries inα-Fe

et al. 2012

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The energetics and length scales associated with the interaction between point defects (vacancies and self-interstitial atoms) and grain boundaries in BCC Fe was explored. Molecular statics simulations were used to generate a grain boundary structure database that contained ≈ 170 grain boundaries with varying tilt and twist character. Then, vacancy and self-interstitial atom formation energies were calculated at all potential grain boundary sites within 15Å of the boundary. The present results provide detailed information about the interaction energies of vacancies and selfinterstitial atoms with symmetric tilt grain boundaries in iron and the length scales involved with absorption of these point defects by grain boundaries. Both low and high angle grain boundaries were effective sinks for point defects, with a few low-Σ grain boundaries (e.g., the Σ3{112} twin boundary) that have properties different from the rest. The formation energies depend on both the local atomic structure and the distance from the boundary center. Additionally, the effect of grain boundary energy, disorientation angle, and Σ-designation on the boundary sink strength was explored; the strongest correlation occurred between the grain boundary energy and the mean point defect formation energies. Based on point defect binding energies, interstitials have ≈ 80% more grain boundary sites per area and ≈ 300% greater site strength than vacancies. Last, the absorption length scale of point defects by grain boundaries is over a full lattice unit larger for interstitials than for vacancies (mean of 6-7Å vs. 10-11Å for vacancies and interstitials, respectively).

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Section: A Examining the Structures And Energies Of Symmetric Tilt Gmentioning

confidence: 99%

Probing grain boundary sink strength at the nanoscale: Energetics and length scales of vacancy and interstitial absorption by grain boundaries inα-Fe

et al. 2012

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“…He can be produced in the structural materials by nuclear transmutation (n, α) through neutron irradiation. Due to its low solubility, He can be deeply trapped in lattice defects, such as dislocations [1][2][3], grain boundaries [4][5][6], precipitates [7,8], especially vacancy and vacancy clusters [9][10][11][12][13][14][15], inducing bubble formation and void swelling, which would cause high-temperature embrittlement of materials [16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

First-principles study on the solute-induced low diffusion and self-trapping of helium in fcc iron

Rao,

Hu,

Ouyang

et al. 2022

Preprint

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The addition of alloying elements plays an essential role in helium (He) behaviours produced by transmutation in metal alloys. Effects of solutes (Ni, Cr, Ti, P, Si, C) on the behaviours of He and He-He pair in face-centred cube (fcc) iron have been investigated using first-principles calculations based on density functional theory (DFT). For the interactions of solutes and He, we found that Ti, P, Si, and C attracts He is more potent than Ni and Cr in fcc iron. We have determined the most stable configuration for the He-He pair, which is the He sub -Hetetra pair with a binding energy of 1.60 eV. In considering the effect of solutes on the stability of the He-He pair, we have proposed a unique definition of binding energy. By applying the definition, we suggest that Ti and P could weaken He self-trapping, and Cr and C are beneficial for He self-trapping, while Ni is similar to the matrix Fe itself. For the diffusion of He, which is the necessary process of forming the He bubble, we determined that the most stable interstitial He is in a tetrahedral site and could migrate with the energy barrier of 0.16 eV in pure fcc iron. We further found that Ti and Si can increase the barrier to 0.18 and 0.20 eV; on the contrary, Cr and P decrease the barrier to 0.10 and 0.06 eV, respectively. Summarizing the calculations, we conclude that Ti decreases while Cr increases the diffusion and self-trapping of He in fcc iron.

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“…Further studies with the updated potentials, involving Hen-Vm clusters interacting with the edge dislocation, have shown that He-rich clusters are attracted to the tensile dislocation region, while vacancyrich clusters are attracted to both dislocation sides [26]. Wang et al [27] reported that a thermally stable He3 cluster exhibits 1D migration in the core of the edge dislocation, in fact, the cluster moves faster on the dislocation line than in bulk. This result raises a question about the possibility of 1D-pipe diffusion not only on the straight dislocation but also on the dislocation loop.…”

Section: Introductionmentioning

confidence: 99%

Interaction of He and He–V clusters with self-interstitials and dislocations defects in bcc Fe

Terentyev

Anento

Serra

et al. 2015

Journal of Nuclear Materials

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The understanding of helium effects in synergy with radiation damage is crucial for the development of structural steels for fusion applications. Recent investigations in ultra-pure iron, taken as a basic model, have shown a drastic impact of dual beam (He-Fe) exposure on the accumulation of radiation-induced dislocation loops in terms of strong bias towards a0/2<111> family, while a0<100> loops are mostly observed upon Fe ion beam. In this work we perform a series of atomistic studies to rationalize possible mechanisms through which He could affect the evolution of microstructure and bias the population of a0/2<111> loops.Strong suppression of a0/2<111> loop migration, prohibiting their mutual interaction resulting in the formation of a0<111> and disappearance at sinks, is proposed to be caused by the He decoration occurring via helium-loop drag mechanism. A scenario for the microstructural evolution in the single-and dual-beam conditions is discussed.

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Effects of edge dislocations on interstitial helium and helium cluster behavior in α-Fe

Cited by 41 publications

References 26 publications

Probing grain boundary sink strength at the nanoscale: Energetics and length scales of vacancy and interstitial absorption by grain boundaries inα-Fe

Probing grain boundary sink strength at the nanoscale: Energetics and length scales of vacancy and interstitial absorption by grain boundaries inα-Fe

First-principles study on the solute-induced low diffusion and self-trapping of helium in fcc iron

Interaction of He and He–V clusters with self-interstitials and dislocations defects in bcc Fe

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