Unique dislocation loops distribution of AlCrFeNiTix eutectic high-entropy alloys under high-temperature ion irradiation

Eutectic high-entropy alloys (EHEAs) have drawn great attention due to their excellent high-temperature mechanical properties. A group of EHEAs AlCrFeNiTix with different titanium contents was irradiated with 3 MeV Fe11+ ions at 500 degrees C with fluences of 9.1 x 1014 and 4.55 x 1015 ions/cm2. The disordered body -centered-cubic (BCC, A2) exhibited smaller-sized dislocation loops than those of ordered BCC (B2) based on Transmission electron microscopy (TEM) analysis. The type of loops found in AlCrFeNi alloy were < 100 > and 1/2 < 111 > . The fraction of 1/2 < 111 > was higher, indicating the excellent irradiation resistance of EHEAs. Small size and large density of dislocation loops formed after the addition of Ti. Phase boundaries in the alloys could effectively decrease the density and size of dislocation loops because of defects annihilation at phase boundaries. In combination with density function theory (DFT) results. B2 phase exhibited better energy landscape advantage in the Ti accommodating, and the MSD results indicated that the lattice dis-tortion effect caused by Ti entering B2 phase was more obvious than A2 according to the density function theory (DFT) results. Our research exhibited a beneficial scheme for solid solution strengthening of ele-ments in EHEAs, and provided an insight into the suppression of dislocation loops under irradiation. (c) 2023 Elsevier B.V. All rights reserved.