Designing TiVNbTaSi refractory high-entropy alloys with ambient tensile ductility

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 brit-tle TiVNbTaSi0.1 via a simple hot rolling process. Hot processing effectively refines the microstruc-tures 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 degrees C. These exceptional performances of TiVNbTaSi0.1 highlight its great potential for high-temperature applications. (c) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

By alloying Si with TiVNbTa and conducting hot rolling process, the TiVNbTaSi0.1 alloy shows exceptional high-temperature oxidation resistance and mechanical properties, highlighting its great potential for applications in high-temperature environments.