Role of Intermetallic Precipitates in Hydrogen Uptake of Zircaloy-2

Hatano, Yuji; Isobe, K.; Hitaka, R.; Sugisaki, Masayasu

doi:10.1080/18811248.1996.9732036

Cited by 26 publications

(6 citation statements)

References 9 publications

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“…Locations in the growing oxide layers that have been proposed for the trapping of hydrogen (deuterium) during the corrosion of zirconium alloys include SPPs [15,17], small cracks or porosity [60,61] and the characteristic larger cracks [62]. To address the possibility of trapping by SPPs, we stopped a NanoSIMS measurement when bright deuterium hot spots were identified in the middle of an oxide layer (about 1 µm below the surface) on sample Z4-2, and then reset the detectors to 52 Cr 16 O -, 56 Fe 16 O -, 58 Ni 16 Oand 120 Snions to determine the locations of SPPs.…”

Section: Correlating Second Phases and Deuterium Distributionsmentioning

confidence: 99%

“…This observation does not agree with several previous reports. Hatano et al [17] suggested that hydrogen transport through oxide layers was via SPPs, which presumably requires preferential segregation to these features. However, the relatively poor lateral resolution of 600 µm in their experiments made it difficult to show that the much smaller intermetallic precipitates were the locations of trapped deuterium.…”

Section: Correlating Second Phases and Deuterium Distributionsmentioning

confidence: 99%

“…There have also been several suggestions for the critical pathways for hydrogen penetration through the oxide based on SIMS analysis. Second Phase Particles (SPPs) have been proposed as preferential diffusion pathways [15][16][17], although the interparticle spacing is usually not small enough to offer a continuous permeation path. Cracks and pores [6], interconnected porosity [18,19] and oxide grain boundaries [20,21] have all been suggested as preferential pathways for hydrogenic, as well as oxidising, species to reach the metal surface.…”

Section: Introductionmentioning

confidence: 99%

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Characterisation of deuterium distributions in corroded zirconium alloys using high-resolution SIMS imaging

Liu

Sayers

et al. 2020

Acta Materialia

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Section: Correlating Second Phases and Deuterium Distributionsmentioning

confidence: 99%

Section: Correlating Second Phases and Deuterium Distributionsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Characterisation of deuterium distributions in corroded zirconium alloys using high-resolution SIMS imaging

Liu

Sayers

et al. 2020

Acta Materialia

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“…There are several previous reports of the value of depth profiling and 3D characterization of zirconium alloys for nuclear applications by SIMS. For example the study of hydrogen or deuterium diffusion through oxides on Zr alloys, 11,7,12,13 the incorporation of cations like Li Na and K into zirconium oxide 14 and the study of second phase particles (SPPs) 15–17 . Recently, we have shown that high‐resolution SIMS analysis of oxidised zirconium alloys using a CAMECA NanoSIMS 50 instrument enables the 3D characterisation of deuterium distributions 9,18 …”

Section: Introductionmentioning

confidence: 99%

Site‐specific specimen preparation for SIMS analysis of radioactive samples

Liu

Lozano-Pérez

et al. 2020

Journal of Microscopy

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Secondary Ion Mass Spectrometry is an important technique for the study of the composition of a wide range of materials because of the exceptionally high sensitivity that allows the study of trace elements and the ability to distinguish isotopes that can be used as markers for reactions and transport processes. However, when studying nuclear materials, it is often necessary to analyse highly radioactive samples, and only rather few SIMS facilities are available in active environments. In this paper, we present a methodology using focussed ion beam milling to prepare samples from radioactive specimens that are sufficiently large to undertake SIMS mapping experiments over microstructurally significant regions, but with overall activities small enough to be readily transported and analysed by a SIMS instrument in a normal laboratory environment. Radioactive samples prepared using this methodology can also be used for correlative SIMS analysis with other analytical microscopies. SIMS results showing the distributions of deuterium in oxides on in‐reactor corroded zirconium alloys are presented to demonstrate the potential of this sample preparation technique.

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“…The alloying elements (Cr, Fe, Ni, Sn) added to produce the Zircaloy-2 alloy influence the material's mechanical properties and corrosion resistance. 4 Due to their low solubility in Zr, Cr, Fe, and Ni segregate to stabilize the β-phase (primarily forming Zr(Fe, Cr) 2 and Zr 2 (Fe, Ni) intermetallics), 1,[5][6][7][8][9] while Sn dissolves in the stable α-phase matrix. 5,10 Recently, we have been studying the properties of oxides on Ti 11,12 and Zr alloys.…”

mentioning

confidence: 99%

Pathways for Hydrogen Absorption into Zircaloy-2 under Cathodic Polarization Assessed by Scanning Electrochemical Microscopy, Scanning Electron Microscopy, and Electrochemical Impedance Spectroscopy

Nowierski

Noël

Shoesmith

et al. 2012

J. Electrochem. Soc.

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Hydrogen absorption by Zircaloy-2 has been studied in neutral sodium sulfate solutions using steady-state polarization measurements, electrochemical impedance spectroscopy (EIS), and scanning electrochemical microscopy (SECM). For applied potentials < −1 V (vs. saturated calomel electrode, SCE), water reduction occurs in faults in the passive oxide covering the alloy. For potentials ≤−1.3 V SCE , SECM detects a distribution of reactive locations on the electrode surface. Matched SECM and SEM images of the same electrode surface show more reactive sites to be located in the β-phase grain boundaries than on the α-grains. The reactivity of surface locations was determined using SECM probe approach curves. Secondary phase particles incorporating impurities such as Fe, Ni, and Cr as Zr(Fe, Cr) 2 and Zr 2 (Fe, Ni) are particularly reactive spots, which may act as "windows" for hydrogen absorption into the alloy. This claim is supported by the observation that the surface of the α-grains remains passive even at potentials as low as −2.0 V SCE . The need to include a Warburg impedance element in modeling EIS recorded at potentials ≥−1.3 V SCE suggests that H 2 O reduction is confined to tight flaws in the oxide at grain boundary locations.

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Role of Intermetallic Precipitates in Hydrogen Uptake of Zircaloy-2

Cited by 26 publications

References 9 publications

Characterisation of deuterium distributions in corroded zirconium alloys using high-resolution SIMS imaging

Characterisation of deuterium distributions in corroded zirconium alloys using high-resolution SIMS imaging

Site‐specific specimen preparation for SIMS analysis of radioactive samples

Pathways for Hydrogen Absorption into Zircaloy-2 under Cathodic Polarization Assessed by Scanning Electrochemical Microscopy, Scanning Electron Microscopy, and Electrochemical Impedance Spectroscopy

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