@article{77123fc6c5764f989d5a6d1cfd66e353,
title = "Evidence of hydrogen trapping at second phase particles in zirconium alloys",
abstract = "Zirconium alloys are used in safety–critical roles in the nuclear industry and their degradation due to ingress of hydrogen in service is a concern. In this work experimental evidence, supported by density functional theory modelling, shows that the α-Zr matrix surrounding second phase particles acts as a trapping site for hydrogen, which has not been previously reported in zirconium. This is unaccounted for in current models of hydrogen behaviour in Zr alloys and as such could impact development of these models. Zircaloy-2 and Zircaloy-4 samples were corroded at 350 °C in simulated pressurised water reactor coolant before being isotopically spiked with 2H2O in a second autoclave step. The distribution of 2H, Fe and Cr was characterised using nanoscale secondary ion mass spectrometry (NanoSIMS) and high-resolution energy dispersive X-ray spectroscopy. 2H− was found to be concentrated around second phase particles in the α-Zr lattice with peak hydrogen isotope ratios of 2H/1H = 0.018–0.082. DFT modelling confirms that the hydrogen thermodynamically favours sitting in the surrounding zirconium matrix rather than within the second phase particles. Knowledge of this trapping mechanism will inform the development of current understanding of zirconium alloy degradation through-life.",
author = "Christopher Jones and Vidur Tuli and Zaheen Shah and Mhairi Gass and Burr, {Patrick A.} and Michael Preuss and Moore, {Katie L.}",
note = "Funding Information: The NanoSIMS was funded by UK Research Partnership Investment Funding (UKRPIF) Manchester RPIF Round 2. This work was supported by the Henry Royce Institute for Advanced Materials, funded through EPSRC Grants EP/R00661X/1, EP/S019367/1, EP/P025021/1 and EP/P025498/1. Some of this work was supported by UK EPSRC grant EP/M017540/1 and EP/S01702X/1 (MIDAS) and Michael Preuss would also like to acknowledge his EPSRC Leadership Fellowship funding EP/I005420/1. We would like to thank Jacobs for supplying the autoclave facilities used in creating the samples in this work and for the financial support provided to this project. This work is part of a larger project, which is funded in part by the Engineering and Physical Sciences Research Council through the Centre for Doctoral Training in Materials for Demanding Environments, Grant EP/L01680X/1. The work was carried out within the framework of the MUZIC (Mechanistic Understanding of ZIrconium Corrosion) program, and we would like to acknowledge all the industry partners, in particular Westinghouse Electric Sweden, for their financial support. Computational facilities were provided by the National Computational Infrastructure (NCI), the MASSIVE HPC facility (www.massive.org.au), and the Pawsey Supercomputing Centre (www.pawsey.org.au), which are supported by the Australian Government, through the Intersect, NCMAS, Pawsey Energy and Resources and UNSW-NCI partner schemes. The research was enabled by Intersect Australia Limited. Learn more at www.intersect.org.au. Publisher Copyright: {\textcopyright} 2021, The Author(s). Copyright: Copyright 2021 Elsevier B.V., All rights reserved.",
year = "2021",
month = feb,
day = "23",
doi = "10.1038/s41598-021-83859-w",
language = "English",
volume = "11",
journal = "Scientific Reports",
issn = "2045-2322",
publisher = "Nature Publishing Group",
number = "1",
}