Hydrogen–vacancy interaction in bcc iron: <i>ab initio</i> calculations and thermodynamics

Мирзаев, Д. А.; Мирзоев, А. А.; Okishev, K. Yu.; Верховых, А.В.

doi:10.1080/00268976.2013.861087

Cited by 42 publications

(21 citation statements)

References 27 publications

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“…At the time, H-vacancy binding was thought to be too small, about 0.4 eV 36 , to account for the permeation lag in deformed materials. However, the DFT results in Box 1, and similar calculations by other investigators 27,37 , show that H-vacancy binding is large, 0.6 eV, and that a single vacancy can trap multiple H atoms.…”

Section: The Large Binding Energy Of 06 Ev For H-vacancy Pairs Suggesupporting

confidence: 61%

The Hydrogen Cold Work Peak in BCC Iron: Revisited, with First Principles Calculations and Implications for Hydrogen Embrittlement

2018

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We examine experimental and theoretical results on the cold-work (Snoek-Köster) peak in bcc Fe due to H using density functional theory (DFT). We reaffirm that Seeger's interpretation of the H cold-work peak (Hcwp), involving motion of H with kinks on non-screw dislocations associated with the intrinsic-dislocation α peak, has experimental backing. Use of the solute-dragging theory of Schoeck suggests a H-mixed dislocation binding energy of 0.3 eV. The theory of Hirth, that the Hcwp involves H-screw dislocation interaction manifested as the temperature-reduced intrinsic-dislocation γ peak by the presence of H, has merit in that our DFT calculations disclose a similar magnitude, 0.2 eV, of H-screw dislocation binding. This result offers support for models of H-enhanced localized plasticity of H embrittlement. We also explore possible roles of H-vacancy binding, shown by DFT to be characterized by a binding energy of 0.6 eV, in H trapping and H embrittlement and lesser effects of H-solute binding involving small binding energies of ~ 0.1 eV.

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Section: The Large Binding Energy Of 06 Ev For H-vacancy Pairs Suggesupporting

confidence: 61%

The Hydrogen Cold Work Peak in BCC Iron: Revisited, with First Principles Calculations and Implications for Hydrogen Embrittlement

2018

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“…Though the present analysis showed that the trapped hydrogen at vacancy is the lowest in each material, however, the coupling of hydrogen with vacancies lowered the vacancy formation energy and resulted in a drastic increase of vacancy concentration [52][53][54]. The vacancy defects occupied by H atoms cluster to form platelets on (111) planes of Al and lead to void formation or crack nucleation on (111) plane [45,55].…”

Section: Discussionmentioning

confidence: 87%

Combined microtomography, thermal desorption spectroscopy, X-ray diffraction study of hydrogen trapping behavior in 7XXX aluminum alloys

Bhuiyan

Toda

Zhang

et al. 2016

Materials Science and Engineering: A

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In the present study, combined thermal desorption spectroscopy (TDS), microtomography and X-ray diffraction study has been carried out to identify the hydrogen trap sites in 7XXX aluminum alloys. Through constant heating rate TDS experiments, three distinct trap states have been identified. It is revealed that micropores are the predominant hydrogen trap site in alloys with medium hydrogen content, whereas grain boundaries is the major hydrogen trap site in alloys with low and high hydrogen content. We have clarified that the rate of trap site occupancy in grain boundaries is high compared to dislocations and vacancies. Such high hydrogen coverage at grain boundaries indicates that the hydrogen-assisted fracture would be intergranular.

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“…Trapping energies of H n V clusters as a function of n according to DFT calculations done by Tateyama and Ohno, [ 34 ] Hayward et al, [ 88 ] Mirzaev et al, [ 36 ] and Oshawa et al [ 89 ] …”

Section: The Interaction Of Microstructural Defects With Hydrogen Revealed By Ifmentioning

confidence: 99%

The Potential of the Internal Friction Technique to Evaluate the Role of Vacancies and Dislocations in the Hydrogen Embrittlement of Steels

Vandewalle

Konstantinović

Depover

et al. 2021

steel research int.

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Hydrogen embrittlement of steels is known to have considerable impact in many engineering sectors. To be able to mitigate the hydrogen embrittlement problem, a profound comprehension of the interaction of hydrogen with the steel microstructure is required. Especially the interaction of hydrogen with dislocations and vacancies is very relevant as these defects are known to play an important role in hydrogen embrittlement. At present, thermal desorption spectroscopy is mostly used to study hydrogen–defect interactions. However, information obtained solely by this technique is insufficient to obtain a full understanding of the interaction of hydrogen with these defects in the steel microstructure. Herein, the use of internal friction, as a complementary technique to thermal desorption spectroscopy, to reveal the interaction of hydrogen with dislocations and vacancies, is reviewed based on the present understanding in the literature. Furthermore, the opportunities to use internal friction to characterize the interaction between hydrogen and these defects and to give more insight into the hydrogen embrittlement mechanism are discussed. It is demonstrated that internal friction has not yet been used to its full potential for this purpose, although it entails the opportunity to develop fundamental insights into the hydrogen embrittlement phenomenon.

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Hydrogen–vacancy interaction in bcc iron: ab initio calculations and thermodynamics

Cited by 42 publications

References 27 publications

The Hydrogen Cold Work Peak in BCC Iron: Revisited, with First Principles Calculations and Implications for Hydrogen Embrittlement

The Hydrogen Cold Work Peak in BCC Iron: Revisited, with First Principles Calculations and Implications for Hydrogen Embrittlement

Combined microtomography, thermal desorption spectroscopy, X-ray diffraction study of hydrogen trapping behavior in 7XXX aluminum alloys

The Potential of the Internal Friction Technique to Evaluate the Role of Vacancies and Dislocations in the Hydrogen Embrittlement of Steels

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