Studies of Hydrogen Trapped by Nitrogen or Oxygen in Niobium With Ultrasonic Attenuation Technique and Resistivity Measurements

Shi, San-Qiang; Li, W.B.

doi:10.1051/jphyscol:19851020

Cited by 5 publications

(7 citation statements)

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“…The energies of strain-induced interaction of interstitial atoms were used for the calculation of the peak temperature, max T , of hydrogen-induced internal friction peaks. It is known that the 'hydrogen Snoek-type maximum' is caused by the diffusion under stress of H or D atoms near immobile O or N atoms [72][73][74][75][76][77][78]. Therefore for such calculations one needs values for the energies of H-H(D-D) and H(D)-O(N) interaction.…”

Section: Hydrogen Internal Friction Peak In Nb and Ta [62]mentioning

confidence: 99%

“…Nb-H [73,74] 106 [74,75] 77 [73] 60 [76] 50 [77] 126 [78] The Effect of Plastic Deformation on the Carbon Internal Friction Peak in Austenitic Steels [80] The mechanical response resulting from the dynamic redistribution of interstitial impurity atoms in austenitic steels under an applied external harmonic stress field is a mechanical loss peak (internal friction peak) which occurs at around 525-575 K (at frequency » f 1 Hz) [80]. The peak was first observed by Finkelshtein and Rosin and is now known in the literature as the Finkelshtein-Rosin (FR) peak [81].…”

Section: Alloysmentioning

confidence: 99%

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Strain-Induced Interaction of Dissolved Atoms and Mechanical Relaxation in Solid Solutions. A Review

Blanter

Magalas²

2003

SSP

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The interaction of dissolved atoms affects the arrangement and energies of the atoms and the asymmetry of the distortion field around a dissolved atom and thereby influences the relaxation processes in solid solutions. This review describes the strain-induced model of atom interaction along with selected examples of the model's applications for analysis of the connection between dissolved atom interaction and peculiarities of mechanical relaxations in interstitial and interstitialsubstitutional solid solutions. The strain-induced interaction is long-range, oscillating, anisotropic, and, in some solid solutions, very strong. In all the investigated cases some coordination shells show attraction. The dependence on distance is determined mainly by the type of crystal lattice; for one type of crystal lattice the dependence is determined by the type of interstitials. The energies of interstitial-interstitial (i-i), interstitial-substitutional (i-s) and substitutional-substitutional (s-s) interaction are calculated for many bcc and fcc metal solid solutions. It is found that a straininduced interaction must be supplemented by a short-range screened Coulomb repulsion in the case of i-i interaction and by a short-range 'chemical' interaction in the case of i-s interaction.The model was previously used in the analysis of: (1) the Cr concentration dependence of the carbon Snoek peak temperature in Fe-Cr-C alloys; (2) the influence of Al ordering on the carbon Snoek peak in -Fe; (3) the effect of plastic deformation on the Finkelstein-Rosin carbon peak in austenitic steels; and (4) the calculation of hydrogen internal friction peaks in Nb and Ta. It is demonstrated that the described model can explain many peculiarities of mechanical relaxations in interstitial solid solutions as observed by internal friction (mechanical spectroscopy).

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Section: Hydrogen Internal Friction Peak In Nb and Ta [62]mentioning

confidence: 99%

Section: Alloysmentioning

confidence: 99%

Strain-Induced Interaction of Dissolved Atoms and Mechanical Relaxation in Solid Solutions. A Review

Blanter

Magalas²

2003

SSP

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“…Vacancies can also be injected by the EP process [54,55], and they should be included in this zone. All of these additions create traps for, and complexes with, for hydrogen atoms [20,56]. Since hydrogen diffusion should then be slowed by trapping in this zone, growth of any precipitates that nucleate, even those nucleated on dislocations, occurs much more slowly if at all.…”

Section: Discussionmentioning

confidence: 99%

Combined effects of cold work and chemical polishing on the absorption and release of hydrogen from SRF cavities inferred from resistance measurements of cavity-grade niobium bars

Dzyuba¹,

Cooley²

2014

Supercond. Sci. Technol.

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A series of small fine-grained and single-crystal bars, with strain from 0% (recrystallized) to 50%, were given different amounts of chemical polishing. Four-point resistivity () data was used to characterize the electron scattering from dislocations, hydrogen, and any other trace contaminants. As noted by previous studies, annealed Nb displayed a weak linear increase of (11 K) with polishing time due to hydrogen absorption, and bulk hydrogen concentration did not exceed 15% for 200 µm metal removed. Cold-worked samples displayed steeper slopes with polishing time (after subtracting resistivity due to strain alone), suggesting that dislocations assist the absorption of hydrogen during polishing. Absorption accelerated above 30% strain and 100 µm material removal, with room-temperature hydrogen concentration rising rapidly from 2% up to 5%. This threshold is significant, since superconducting radio-frequency (SRF) cavities are usually polished as-formed, with >35% strain, and polishing removes >150 µm of metal. Resistance jumps between 40 and 150 K, which signal the formation of hydride precipitates, were stronger in cold-worked samples, suggesting that dislocations also assist precipitate nucleation. High-vacuum anneals at 800 °C for 2 hours, which are known to fully recrystallize cavity-grade niobium and de-gas hydrogen, removed the 40-150 K jumps and recovered the resistivity increase due to chemical polishing entirely. But, about 30% of the resistivity increase due to cold work remained, possibly due to residual dislocation clusters. Continued annealing only facilitated the diffusion of surface impurities into the bulk and did not recover the initial 0% state. Strain, polishing, and annealing thus appear to combine as irreversible paths that change the material. Bearing this in mind, the significant difference in hydrogen uptake between annealed and coldworked samples suggests that annealing SRF cavities prior to chemical polishing could greatly reduce hydrogen uptake and storage in the metal, reducing risk of quality-factor loss. This inverts key steps of the present widely-used cavity processing sequence.

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“…It is known that the hydrogen Snoek-type maximum is caused by the diffusion under stress of H or D atoms near the immobile O or N atoms [28][29][30][31][32][33][34]. Therefore for such calculations one needs the values for the H-H(D-D) and H(D)-O(N) interaction energies.…”

Section: Hydrogen Internal Friction Peak In Nb and Ta [12]mentioning

confidence: 99%

“…It was shown that the H-H repulsion for V, Nb and Ta [9] and H-N repulsion for Nb and Ta [9,26] extend up to three coordination shells. Behavior of the hydrogen atoms in Table 2 Comparison of calculated and experimental temperatures of internal friction peaks [12] Alloys (K) 50 [28] 79 [29,30] 106 [30,31] 77 [29] 60 [32] 50 [33] 126 [34] a solid solution is determined both by a repulsion distance and elastic interaction energies outside the radius of repulsion. Computer simulation of the temperature dependence of hydrogen diffusion in Pd, Cu, and Ni with a low hydrogen concentration of 0.11 at.% [9] showed that such additional repulsion is absent.…”

Section: Applicability Limitations Of the Strain-induced Interaction mentioning

confidence: 99%

Hydrogen interaction with dissolved atoms in metal solid solutions

Blanter

Granovskiy²,

Magalas

2005

Journal of Alloys and Compounds

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Studies of Hydrogen Trapped by Nitrogen or Oxygen in Niobium With Ultrasonic Attenuation Technique and Resistivity Measurements

Cited by 5 publications

References 0 publications

Strain-Induced Interaction of Dissolved Atoms and Mechanical Relaxation in Solid Solutions. A Review

Strain-Induced Interaction of Dissolved Atoms and Mechanical Relaxation in Solid Solutions. A Review

Combined effects of cold work and chemical polishing on the absorption and release of hydrogen from SRF cavities inferred from resistance measurements of cavity-grade niobium bars

Hydrogen interaction with dissolved atoms in metal solid solutions

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