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

In the current research, an equimolar (TiZrTa)₅₀Ni₂₅Co₁₀Cu₁₅ 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)₅₀Ni₂₅Co₁₀Cu₁₅ 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.