Effects of oversized element Sn on diffusion of interstitial clusters in Ni irradiated by ions and neutrons

Effects of damage rate on defect structural development in Ni and Ni–Sn were studied by the comparison of neutron irradiation with Ni ion irradiation. Special attention was paid to the damage structural evolution near grain boundaries which was affected by the one-dimensional (1-D) motion of self-interstitial atom (SIA) clusters. The 1-D motion of SIA clusters was observed in Ni irradiated with low fluence in both cases of neutron irradiation and ion irradiation. The alloying element Sn prevented the 1-D motion. The irradiation temperatures to cause the same damage structural evolution in Ni and Ni–Sn was shifted to high temperatures (200 K and 100 K, respectively) with increasing damage rate.