Use of oxygen isotope to study the transport mechanism during high temperature oxide scale growth

Mechano-Chemical Aspects of High Temperature Oxidation: A Mesoscopic Model Applied to Zirconium Alloys

“…In order to estimate the oxide scale thickness which has grown on each oriented surface, we have oxidized our samples using sequential exposure in 16 O 2 and 18 O 2 at 873 K. 43 The total oxidation time was 6 hr. After cooling the samples, in-depth profiles of Zr and O isotopes are obtained by the SNMS technique.…”

The use of micro-Raman imaging to measure 18 O tracer distribution in thermally grown zirconia scales

“…Specifically, the use of the 18 O isotope allows discriminating between anionic, cationic or mixed anionic + cationic transport mechanisms involved in formation of protective Thermally Grown Oxides (TGO) [19][20][21]. Analysis of the 18 O in-depth diffusion profiles can lead to the determination of the oxygen bulk and grain boundary diffusion coefficients [4,20,[22][23][24].…”

“…Analysis of the 18 O in-depth diffusion profiles can lead to the determination of the oxygen bulk and grain boundary diffusion coefficients [4,20,[22][23][24]. Secondary Ions Mass Spectroscopy (SIMS) or Secondary Neutral Mass Spectroscopy (SNMS) are, most often, the techniques used to track the isotope distribution in the scale after a two-stage oxidation experiment [18,21,[25][26][27]. As an alternative, Nuclear Reaction Analysis (NRA) is sometimes used: quantitative 18 O deep profiles can be directly obtained from the energy spectrum of the ␣ particles produced by the 18 O(p,␣) 15 N reaction [4,27,28].…”

Understanding of Hybriding Mechanisms of Zircaloy-4 Alloy during Corrosion in PWR Simulated Conditions and Influence of Zirconium Hybrides on Zircaloy-4 Corrosion

“…O, a deeper penetration of 18 O is observed in the oxide scale formed on the pre-hydrided samples, leading to a twice higher diffusion coefficient of oxygen (2.4.10 -15 cm²/s compared with 1.3.10 -15 cm²/s for the reference sample, with this last result in accordance with bibliography [31]). Moreover, in both kinetic domains (pre-and post-transition), a higher concentration of 18 O in the fast diffusion paths (grain boundaries, probably) can be observed on the pre-hydrided samples, as well as a faster enrichment of 18 O near the internal interface, which is the sign of a higher part of diffusion through the grain boundaries in corrosion films formed on hydrogen-containing samples [32]. A model based on a different structure of grain boundaries in zirconia formed on the pre-hydrided and the reference samples has been proposed [33].…”