Irradiation-induced swelling and hardening in HfNbTaTiZr refractory high-entropy alloy.

• The irradiation-induced swelling effect were significantly suppressed in HfNbTaTiZr refractory high-entropy alloy. • The nanoindentation hardness after the irradiation was almost unchanged. • The radiation damage range far exceeded the simulated results and the range of implanted species. The lattice distortion and diffusion kinetics of refractory high-entropy alloys (RHEAs), which may be endowed with superior radiation tolerance, render RHEAs candidate materials for nuclear and aerospace systems. To investigate the irradiation behavior of body-centered cubic (BCC) RHEAs, the specimens were irradiated by 300 keV Ni+ to a fluence of 1.5 × 1016 cm−2 at 100 °C, reaching a high damage level to over 30 displacements per atom (dpa). The results revealed that the swelling and hardening effects were significantly suppressed compared to those of conventional nuclear materials. Further microstructural characterization showed that the damage range far exceeded the simulated results and the range of implanted species. [ABSTRACT FROM AUTHOR]