Enhanced plasticity in a Zr-rich refractory high-entropy alloy via electron irradiation

Abstract

Refractory high-entropy alloys (RHEAs) possess remarkable high-temperature mechanical properties and have significant potential for use in nuclear fission reactors. However, the phase stabilities of RHEAs are relatively poor in the intermediate temperature range. The coarsening of the nanoprecipitates weakens the plasticity of RHEAs, which imposes substantial restrictions on their scope of application. In this study, electron irradiation was employed to address the challenges associated with nanoprecipitate coarsening and discontinuous precipitation in Zr35Ti30Nb20Al10Ta5 RHEAs after intermediate-temperature annealing. Electron irradiation caused the B2 nanoprecipitates to dissolve, re-precipitate, and induce the precipitation of omega nanoprecipitates. Compared with the unirradiated Zr35Ti30Nb20Al10Ta5 RHEAs with poor plasticity (fracture before yielding), the elongation of irradiated Zr35Ti30Nb20Al10Ta5 RHEAs reaches up to 10 %. This study provides a unique viewpoint and pioneering methodology to effectively tackle the challenge of inadequate plasticity in RHEAs.