Designing TiVNbTaSi refractory high-entropy alloys with ambient tensile ductility

• Good ductility of TiVNbTa was confirmed by tensile tests for the first time • Hot rolling induces nanoprecipitates and improves the strength-ductility synergy of TiVNbTaSi 0.1 . • TiVNbTaSi 0.1 exhibits excellent oxidation resistance and high-temperature phase stability. Adding oxidation-resistant elements (e. g. Al, Cr, Si) to refractory high-entropy alloys (RHEAs) improves their high-temperature oxidation resistance while commonly degrades the room-temperature ductility, which greatly challenges the further applications of RHEAs. To tackle this trade-off, here in this study, we first identified the tensile-ductile TiVNbTa, alloyed it with Si, and then ductilized the initially brittle TiVNbTaSi0.1 via a simple hot rolling process. Hot processing effectively refines the microstructures of TiVNbTaSi0.1 and induces high-density nano-silicides, which contributes to the unprecedented mechanical properties of ∼1250MPa yield strength and ∼8% tensile ductility. Compared with reported ductile RHEAs, TiVNbTaSi0.1 shows superior oxidation resistance and both TiVNbTa and TiVNbTaSi0.1 demonstrate improved phase stabilities at temperatures >500 °C. These exceptional performances of TiVNbTaSi0.1 highlight its great potential for high-temperature applications.