High temperature oxidation behavior of high entropy alloy Al4Co3Cr25Cu10Fe25Ni33 in oxygen-containing atmospheres

High entropy alloys (HEAs) have recently attracted considerable interest and attention due to their novel properties of good corrosion resistance and superior mechanical strength at high temperatures. In this study, we investigated the oxidation behavior of a new high entropy alloy, Al4Co3Cr25Cu10Fe25Ni33, by using thermogravimetric analyzer at temperatures ranging from 800 degrees C to 950 degrees C under atmosphere of Ar and O-2 for 24 h. The results showed that the oxidation kinetics of Al4Co3Cr25Cu10Fe25Ni33 alloy followed a parabolic regime with its rate constant steadily increased with increasing temperature. The activation energy of Al4Co3Cr25Cu10Fe25Ni33 alloy was found to be 178 kJ/mol. In addition, the bilayer scales and the internal oxidation behavior at the grain boundaries of Al4Co3Cr25Cu10Fe25Ni33 alloy were also examined and discussed.