Oxidation Behavior of Alx(CoCrFeNi)100-x High-Entropy Alloys Under Thermal-Cycling Conditions

Abstract The oxidation behavior of five different high-entropy alloys from the Al–Co–Cr–Fe–Ni metallic system, namely Al x (CoCrFeNi) 100- ( = 0; 3; 6; 9; 12), was studied under thermal-cycling conditions, at 1273 K in air atmosphere. choice selected compositions allowed for covering chromia-to-alumina former transition, as well transition FCC single-phase solid solution structure to multiphase with Al-enriched B2-structured constituent. measurements were taken 500 cycles (1 cycle - 1 h heating, 20 min cooling). results indicate a profound influence conditions on products, extremely complex scale structures and extensive internal nitridation zones, severe spallation oxide most cases, showing limited usefulness these high-temperature applications current stage their development.