Effect of Al content on high-temperature oxidation behavior and failure mechanism of CrAl-coated Zircaloy

The application of coating to cladding materials can potentially improve the accident-tolerant fuel cladding for light water reactors. In this study, oxidation behavior of five CrAl-based coatings containing different amounts of Al deposited onto Zr-4 alloy exposed to high-temperature air is investigated. The results demonstrate that pure Cr coating exhibits excellent oxidation resistance due to the formation of dense and continuous Cr2O3 oxide. By contrast, loose coatings with high Al contents correspond to poor oxidation resistance, which is related to the reaction between Zr and O. This paper proposes that the oxidation failure mechanisms of coatings depend on Al content. The raw/processed data required to reproduce these findings cannot be shared at this time as the data also forms part of an ongoing study. •CrAl-based coatings deposited onto Zr-4 alloy are prepared.•Pure Cr coating exhibits optimal resistance to oxidation.•The constituents of oxide coatings depend on Al content.•Oxidation failure mechanisms of CrAl-based coatings correlate with Al content.