Microstructure evolution in Cr_0.6FeNiMn and CrFeNiCoPd under ion irradiation

It has been suggested that CrFeNi-based multi-principal element alloys (MPEAs) may be attractive materials for nuclear energy applications due to promising mechanical properties and possible increased resistance to irradiation damage compared to traditional alloys. However, phase stability during irradiation at intermediate temperatures remains a concern and expanding the range of irradiation conditions is of prime importance to understand the radiation damage mechanisms operating in these alloys. Here, the effects of dose and dose rate on the microstructures of two model alloys, Cr_0.6FeNiMn and CrFeNiCoPd, during heavy ion irradiation were investigated. Both alloys exhibited phase decomposition under thermal aging and ion irradiation. Under ion irradiation, the decomposition process followed a thermodynamically driven radiation-enhanced diffusion process that is susceptible to cascade mixing effects at high ion irradiation dose rates.