The Effect of Annealing Temperature on the Microstructure and Properties of Cr–C–Al Coatings on Zircaloy-4 for Accident-Tolerant Fuel (ATF) Applications

Elemental Cr/C/Al multilayers (stoichiometric ratio: 2:1:1) with and without a Cr overlayer have been synthesized on Zircaloy-4 substrates by magnetron sputtering. The effects of annealing temperatures (400 550 °C) phase/microstructure formation, mechanical properties, oxidation/corrosion performance comparatively studied. Annealing the at 400 °C led to formation nanocrystalline composite consisting intermetallic binary carbide phases. Single-phase Cr2AlC was obtained after annealing, but microcracking coatings. Both annealed coatings displayed similar high-temperature oxidation, hydrothermal corrosion mechanisms. significantly enhance oxidation resistance (?-Al2O3 scale growth) (Cr2O3 passivation layer formation) substrate coating delamination. Nanocomposite CrCAl-based are promising candidates for coated ATF applications acceptable processing excellent resistances zirconium alloy substrate.