The isothermal oxidation behavior of multi-component high entropy alloys (HEAs), namely AlCuCrFeMn, AlCuCrFeMnW0.05, AlCuCrFeMnW0.1, and AlCuCrFeMnW0.5, was investigated and the behavior of the oxide layer was analyzed. All four HEAs were synthesized via mechanical alloying (MA) and consolidated by spark plasma sintering (SPS). The samples were oxidized in the air atmosphere at a temperature of 500 °C for 50 h. Based on the thermogravimetric result, the oxidation rate of the materials decreased with the increase of W content, and the values of parabolic constants were on a level similar to those observed in Ni-Al superalloys. However, higher content of W improves the continuity and internal position of the WO3 scale, which leads to increased oxidation resistance. Throughout the oxidation process, the composition of the phases of all materials changed significantly. The triple-thick oxide layer formed of Al2O3, Cr2O3, and WO3, developed in HEAs, has been carefully studied using the XPS technique.
VK, DK, and SKD are grateful to BRNS Project No. 34/20/01/2014-BRNS-0339, Mumbai (India) for financial assistance, and thank Dr. VK Sharma & Dr. YVSS Prasad for their help. This work was supported by a National Research Foundation of Korea (NRF) grant funded by the Korean Government ( MSIT ) (No. 2021R1A2C1005478) [BA]. This research was also supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Education (Nos. 2022R1I1A1A01053047 and 2021R1A6A1A10044950) [SKD].
