Growth rate of dislocation loop in FeNiCr alloy under Kr + ion and electron irradiation

Abstract

In order to examine the effect of irradiating particle species on the growth rate of radiation-induced dislocation loops, a solution-annealed Fe25Ni15Cr0.02C alloy was irradiated at 723 K first by (1) 1.5 MeV Kr + ions for 2520 s, then by (2) 1.5 MeV Kr + ions and 1.0 MeV electrons simultaneously for 780 s, and finally by (3) 1.0 MeV electrons for 780 s with the HVEM-tandem facility in Argonne National Laboratory. The calculated damage rate by 1.5 MeV Kr + ions was 5.8 × 10 −4 dpa/s, and that by 1.0 MeV electrons was 1 × 10 −4 dpa/s. The growth rate of a dislocation loop located at the center of the specimen was 7 × 10 −3 nm/s for the Kr + ion irradiation, 4 × 10 −2 nm/s for the simultaneous Kr + and electron irradiation, and (2–3) × 10 −2 nm/s for the electron irradiation. This implies that the electron irradiation is about 19 times more effective in the growth of radiation-induced dislocation loops than the Kr + ion irradiation. The dislocation loop growth rate under the simultaneous Kr + and electron irradiation is higher than the sum of the growth rates under the individual Kr + and electron irradiations.