Effect of Zr/Dy doping on the high-temperature oxidation resistance of NiCrAlY coatings

In this study, three NiCrAlY coatings, both doped and undoped with Dy/Zr, were fabricated on a nickel-based single crystal superalloy using the arc ion plating technique. The influence of Dy/Zr doping on the high-temperature oxidation resistance of NiCrAlY coatings was investigated. After 200 h of oxidation, the oxidation rates of the NiCrAlY, NiCrAlYZr, and NiCrAlYDy coatings were 1.28 x 10-2, 5.38 x 10-2, and 4.10 x 10-3 mg-2 & sdot;cm-4 & sdot;h-1 , respectively. The NiCrAlY coating doped with Zr exhibited severe oxidation with the thickest oxide layer, whereas the Dy-doped NiCrAlY coating showed a thin yet intact oxide layer, demonstrating excellent high-temperature oxidation resistance. However, the Zr-doped NiCrAlY coating displayed the most complete interface/coating structure and inhibited interdiffusion between the coating and substrate, while the Dy-doped NiCrAlY coating had no significant effect on the interdiffusion between the coating and substrate. The results of this study provide valuable insights into the selection of active elements for doping protective coatings.