| Abstract Scope |
Nickel-based multi-principal element alloys (MPEAs) offer promises for nuclear application due to their superior mechanical properties. In addition, as compared to the less concentrated alloys, MPEAs such as CrFeNiCo, CrFeNiMn, CrFeNiCoMn, and CrFeNiCoPd have shown excellent phase stability, high swelling resistance, delayed energy dissipation, and suppressed damage evolution under high dose rate environment (>10^-3 dpa/s). However, these high dose rates are not representative of actual nuclear reactor environment, therefore, understanding the possible effects of dose rates on the irradiation behavior of MPEAs is needed. We investigated the microstructural response of a series of alloys of increasing compositional complexity that were ion irradiated at 10^-4 dpa/s and 10^-5 dpa/s. Transmission electron microscopy and atom probe tomography revealed phase decomposition in CrFeNiMn23 and CrFeNiCoPd MPEAs. In addition, the effect of composition on dislocation loops and cavity swelling was found to significantly decrease with decreasing dose rates. |