Oxidation Behavior of Al8Co17Cr17Cu8Fe17Ni33, Al23Co15Cr23Cu8Fe15Ni15, and Al17Co17Cr17Cu17Fe17Ni17 Compositionally Complex Alloys (High-Entropy Alloys) at Elevated Temperatures in Air

摘要

abstract_textpOxidation behavior of the compositionally complex alloys (high-entropy alloys) Al8Co17Cr17Cu8Fe17Ni33 (fcc-alloy), Al23Co15Cr23Cu8Fe15Ni15 (bcc-alloy), and Al17Co17Cr17Cu17Fe17Ni17 (reference-alloy) at elevated temperatures in air is investigated. The microstructures of the oxide scales and the substrates are analyzed using scanning electron microscopy and X-ray diffraction. All oxidized alloys follow a parabolic kinetic law with low mass change per surface area at 800 degrees C. The Al8Cr17Co17Cu8Fe17Ni33 alloy follows sub-parabolic kinetic law at 1000 degrees C and exhibits good oxidation resistance at both tested temperatures (800 and 1000 degrees C). Two alloys, Al23Co15Cr23Cu8Fe15Ni15 and Al17Co17Cr17Cu17Fe17Ni17 suffer from strong spallation at 1000 degrees C./p/abstract_text