Investigating the high-temperature oxidation behavior of (TiZrTa)50Ni25Co10Cu15 equimolar refractory high entropy alloy

In the current research, an equimolar (TiZrTa) 50 Ni 25 Co 10 Cu 15 refractory high entropy alloy was designed to study its oxidation resistance at high temperatures. The thermodynamic properties proved the alloy to have a dual microstructure, later confirmed by XRD analysis. The microstructural analysis revealed a seaweed-like dendritic structure. The (TiZrTa) 50 Ni 25 Co 10 Cu 15 refractory high entropy alloy proved to show adequate thermal stability at high temperatures when subjected to oxidation tests in DSC/TGA. For comparison, the alloy was oxidized in a tube furnace and a DSC/TGA instrument to show its stability in air. The alloy also maintained its structural and compositional stability at temperatures as high as 1000 °C when oxidized in the air by forming Ti and Ta-rich oxides on the surface and showing no signs of pesting and surface deterioration. However, the workability and ductility of the alloy need to be improved. • The (TiZrTa) 50 Ni 25 Co 10 Cu 15 refractory HEA was designed to study its oxidation resistance at high temperatures. • The alloy exhibited a dual microstructure, confirmed by XRD analysis, with a seaweed-like dendritic structure. • The alloy demonstrated thermal and compositional stability up to 1000 °C without pesting or surface deterioration. • The alloy shows good oxidation resistance; its workability and ductility need improvement.