A study on He ion irradiation damage in (Ti0.25Zr0.25Nb0.25Ta0.25)C high-entropy carbide ceramics from room temperature to 700 °C

High-entropy carbide ceramics (Ti 0.25 Zr 0.25 Nb 0.25 Ta 0.25 )C with a single-phase rock-salt structure were prepared by hot-pressed sintering. These ceramics were irradiated with 500 keV He 2+ ions to fluences of 5 × 10 16 ions·cm −2 and 1 × 10 17 ions·cm −2 at room temperature to 700 °C. The investigation into irradiation-induced lattice swelling was conducted using grazing incident X-ray diffraction, while microstructure evolution was characterized through transmission electron microscopy . Lattice expansion induced by the He ion irradiation was identified, which highly depends on the irradiation temperature and fluence. Notably, the lattice expansion diminishes with rising irradiation temperature primarily as a result of the dynamic annealing effect . Nano-sized He bubbles , with an average diameter of less than 1 nm were uniformly dispersed within the grain interior. Notably, He bubble nucleation does not exhibit a preference for grain boundaries at 700 °C irradiation. Following He ion irradiation at 350 °C and 700 °C, dislocation loops of 1/3<111> and 1/2<110> with sizes in the ranges of several nanometers were observed. The present study provides insights into high-entropy carbide ceramics with potential applications in the field of nuclear energy.