Positron Annihilation in Ni&lt;sub&gt;3&lt;/sub&gt;Al: Theory and Experiment

Petegem, S. Van; Kuriplach, J.; Hou, Marc; Журкин, Е. Е.; Segers, D.; Morales, A.L.; Ettaoussi, S.; Dauwe, C.; Mondelaers, W.

doi:10.4028/www.scientific.net/msf.363-365.210

Cited by 9 publications

(6 citation statements)

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“…The advantage of this method is the detection of small concentrations of defects that could not be detected by other methods. [17] Positron techniques have been used for studies of defect behavior in the Ni 3 Al system [18] and polycrystalline Ni-based superalloys, [19] but there are no results as yet for investigation of defects inhomogeneity in the single-crystalline turbine blades.…”

Section: Introductionmentioning

confidence: 99%

Influence of Heat Treatment on Defect Structures in Single-Crystalline Blade Roots Studied by X-ray Topography and Positron Annihilation Lifetime Spectroscopy

Krawczyk

Bogdanowicz

Hanc-Kuczkowska

et al. 2018

Metall Mater Trans A

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Single-crystalline superalloy CMSX-4 is studied in the as-cast state and after heat treatment, with material being taken from turbine blade castings. The effect of the heat treatment on the defect structure of the root area near the selector/root connection is emphasized. Multiscale analysis is performed to correlate results obtained by X-ray topography and positron annihilation lifetime spectroscopy (PALS). Electron microscopy observations were also carried out to characterize the inhomogeneity in dendritic structure. The X-ray topography was used to compare defects of the misorientation nature, occurring in as-cast and treated states. The type and concentration of defects before and after heat treatment in different root areas were determined using the PALS method, which enables voids, mono-vacancies, and dislocations to be taken into account. In this way, differences in the concentration of defects caused by heat treatment are rationalized.

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Section: Introductionmentioning

confidence: 99%

Influence of Heat Treatment on Defect Structures in Single-Crystalline Blade Roots Studied by X-ray Topography and Positron Annihilation Lifetime Spectroscopy

Krawczyk

Bogdanowicz

Hanc-Kuczkowska

et al. 2018

Metall Mater Trans A

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“…Corresponding positron properties differ from those for a perfect GB. For example, a single vacancy located at the above-mentioned GB in Ni 3 Al (this is no longer a perfect GB) gives quite a long lifetime similar to that for a divacancy in the bulk [19].…”

Section: Positron Annihilation At Open Volume Defectsmentioning

confidence: 92%

Positron annihilation Investigations of defects in copper alloys selected for nuclear fusion technology

Slugeň

Kuriplach

Ballo

et al. 2004

Fusion Engineering and Design

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“…Table 4 shows the calculated positron lifetimes for delocalized positrons and positrons trapped in a mono-vacancy and a di-vacancy in Ni 3 Al. No lattice relaxations were taken into account as their influence on the positron lifetime is restricted to a few picoseconds [32,33]. Within LDA the lifetimes are systematically lower than within GGA.…”

Section: Irradiation Simulationmentioning

confidence: 99%

Effect of Oxygen Adsorption on Polaron Conduction in Nanometer-Scale Nb⁵⁺-, Fe³⁺-, and Cr³⁺-Doped SrTiO₃ Thin Films

Hara

Shinozaki

2011

Jpn. J. Appl. Phys.

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In this paper we study the vacancy creation process in polycrystalline Ni 3 Al under electron irradiation using positron annihilation lifetime spectroscopy. The complete irradiation experiment has been simulated using Monte Carlo and molecular dynamics techniques. This allows us to estimate the absolute vacancy concentration. Comparison with the experimental positron lifetimes results in a positron trapping coefficient for vacancies in Ni 3 Al of 2.8×10 15 s −1 . Furthermore the calculations show that 81% of the vacancies are located on the Ni sublattice. Using these results we discuss the vacancy concentration range in Ni 3 Al for which positron annihilation lifetime spectroscopy is sensitive. Furthermore the annealing behaviour of the irradiated samples is investigated.

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Positron Annihilation in Ni<sub>3</sub>Al: Theory and Experiment

Cited by 9 publications

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Influence of Heat Treatment on Defect Structures in Single-Crystalline Blade Roots Studied by X-ray Topography and Positron Annihilation Lifetime Spectroscopy

Influence of Heat Treatment on Defect Structures in Single-Crystalline Blade Roots Studied by X-ray Topography and Positron Annihilation Lifetime Spectroscopy

Positron annihilation Investigations of defects in copper alloys selected for nuclear fusion technology

Effect of Oxygen Adsorption on Polaron Conduction in Nanometer-Scale Nb⁵⁺-, Fe³⁺-, and Cr³⁺-Doped SrTiO₃ Thin Films

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Positron Annihilation in Ni<sub>3</sub>Al: Theory and Experiment

Cited by 9 publications

References 0 publications

Influence of Heat Treatment on Defect Structures in Single-Crystalline Blade Roots Studied by X-ray Topography and Positron Annihilation Lifetime Spectroscopy

Influence of Heat Treatment on Defect Structures in Single-Crystalline Blade Roots Studied by X-ray Topography and Positron Annihilation Lifetime Spectroscopy

Positron annihilation Investigations of defects in copper alloys selected for nuclear fusion technology

Effect of Oxygen Adsorption on Polaron Conduction in Nanometer-Scale Nb5+-, Fe3+-, and Cr3+-Doped SrTiO3 Thin Films

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Effect of Oxygen Adsorption on Polaron Conduction in Nanometer-Scale Nb⁵⁺-, Fe³⁺-, and Cr³⁺-Doped SrTiO₃ Thin Films