Elemental Influence on Oxidation Behaviour of Cantor-Based and Refractory High Entropy Alloys: A Critical Review

This article reviews the oxidation behaviour of the two most significant high entropy alloy systems (HEAs) namely Cantor-based and refractory HEAs. HEAs have been extensively researched and show potential applications in various industries, including marine engine manufacturing, chemical industry, furnaces, ducting, heat exchangers, jet engines, steam turbines, nuclear reactors and electronic devices, among others. Effect of the presence of elements such as aluminium, manganese, chromium, silicon, tantalum, vanadium etc. is studied for catalysing the oxidation of HEAs. Aluminium, chromium, and silicon are reportedly found to considerably impact the oxidation kinetics and enhance the oxidation resistance. However, silicon can positively or adversely affect the oxidation resistance depending on its concentration and alloy composition. Other elements like manganese tend to adversely impact the oxidation resistance of FeCoNi-based HEAs. Refractory elements are typically found to be not suitable for oxidation studies due to the formation of non-protective oxide layers. However, refractory HEAs offer interesting trends both in terms of enhancing or reducing oxidation resistance depending on the alloying elements. Similarly, findings related to other elements are also presented and elaborated.