Xe20+ ions irradiation and autoclave corrosion coupled with steam oxidation behaviors of FeCrAlMoSiY-coated Zr claddings

Abstract

Surface-modified Zr alloys by protective coatings are being developed as the most viable near-term accident tolerant fuel (ATF) claddings. Herein, an amorphous FeCrAlMoSiY coating was deposited on Zr alloys by magnetron sputtering. The key performance of specimens in terms of ion irradiation, autoclave corrosion, and high-temperature steam oxidation were studied using X-ray diffractometer (XRD), atomic force microscopy (AFM), and scanning electron microscopy (SEM). We found that the surface of the irradiated coating became more compact with a lower surface roughness than the as-deposited coating. Meanwhile, the hardness and indentation modulus decreased slightly after irradiation. After 30 days autoclave corrosion, a continuous spinel FeCr2O4 scale was formed on the surface, and the residual coating had the same composition and ~76% in thickness of that of the as-deposited coating. During the 1200 °C steam oxidation of that corroded sample, the protective α-Al2O3 scale was formed underneath the FeCr2O4 layer, along with the formation of a diffusion barrier at the coating-substrate interface. These findings highlight the potential of the FeCrAlMoSiY coating considered as a protective coating for ATF claddings.