Oxidation Behavior of FeCoNiCrMo High-Entropy Coatings by Atmospheric Plasma Spraying on Zircaloy-4 in Steam at 1100 °C

Abstract

As a potential accident-tolerant fuel cladding material, we studied the method of preparing FeCoNiCrMo coatings on zircaloy-4 substrates by atmospheric plasma spraying (APS) technology to explore the high-temperature oxidation behavior of the FeCoNiCrMo coatings at 1100 °C in high-temperature steam. Various surface analysis techniques such as X-ray diffraction, electron probe microanalysis, and scanning electron microscopy were used to analyze the phase composition and microstructure of the oxidized products. The oxidation behavior of the FeCoNiCrMo coatings and the diffusion of the FeCoNiCrMo coatings to the zircaloy-4 substrates were analyzed. After oxidation at 1100 °C, a dense Cr2O3 oxide layer was formed on the coating’s surface, which grew from 1.5 to 3 μm after 15 to 60 min of oxidation, and the FeCoNiCrMo coatings and the substrates diffused simultaneously. The oxidation tests showed that the FeCoNiCrMo coatings prepared by APS can effectively delay the oxidation of zircaloy-4 substrates.