The influence of Y2O3/CeO2 on the microstructure and properties of AlCrFeNiCu high-entropy alloy coating

Y₂O₃ and CeO₂ nanoparticles were individually incorporated into an AlCrFeNiCu coating applied to the surface of a Zr-4 rod. The microstructure, hardness, high-temperature fretting wear behavior, corrosion resistance, and high-temperature oxidation resistance of the coatings were comprehensively evaluated. The results demonstrate that the addition of Y₂O₃ or CeO₂ notably modified the solidification kinetics of the molten pool, affected elemental diffusion pathways, and effectively refined the grain structure, thus significantly improving the overall performance of the AlCrFeNiCu coating. Specifically, the hardness of the AlCrFeNiCu coatings doped with Y₂O₃ and CeO₂ reached 8.61 GPa and 8.72 GPa, respectively, with corresponding wear rate reductions of 38.0 % and 41.3 % compared to the undoped coating. In a 0.1 mol/L KOH solution, the self-corrosion current densities of both modified coatings decreased by one order of magnitude in comparison to the unmodified AlCrFeNiCu coating. The oxidation behavior of both coatings conformed to parabolic kinetics, and the coatings retained their structural integrity after being exposed to air at 1200 °C for 90 minutes, whereas the undoped coating exhibited microcracks after 30 minutes of exposure.