Abstract Scope |
MPEAs are being considered for nuclear applications because of their potentially superior mechanical properties and irradiation resistance. Of particular interest are Ni-based MPEAs, specifically CrFeNiMn, CrFeNiCoMn, and CrFeNiCoPd with high swelling resistance and suppressed damage accumulation compared to stainless steels and dilute alloys. While these MPEAs appear stable against phase decomposition during high dose rate ion irradiation, electron irradiation and thermal annealing studies suggested that these alloys may be susceptible to phase decomposition. To clarify the role of dose rate during ion irradiation, alloys were irradiated using Fe ions at 5000C with an intermediate dose rate of 10-4 dpa/sec. Transmission electron microscopy and atom probe tomography observations revealed phase decomposition in the Mn and Pd containing alloys with a strong effect on dislocation loop structure. In addition, comparison among the irradiated responses of Cr18Fe39Ni38Mn5, Cr18Fe28Ni31Mn23, and Cr18Fe35Ni35Mn12 unveiled the effects of Mn concentration on phase decomposition and dislocation loop structure. |