In this study, we report a type of ultra oxidation and spallation resistant Y/Hf-doped AlCoCrFeNi high-entropy alloy (HEA). The alloy exhibits a significantly lower oxidation rate at 1100 ℃ with a kp value of about 1.9×10-13 g2 cm-4s-1, which is one magnitude lower than those of the conventional NiCoCrAlY alloys. Additionally, the alloy shows a strong resistance to the oxide scale spallation. The superior oxidation performance for the Y/Hf-doped HEA can be attributed to the fast establishment of exclusive α-Al2O3 scale, the beneficial reactive element effect and the large columnar grain size (width) in the oxide scale.
- High temperature
- High-entropy alloy