Annihilation of interstitial atoms to dislocations in neutron-irradiated Cu and Ni at high temperature

Abstract

When Cu and Ni were irradiated at 300°C by neutrons in a reactor, interstitial clusters decorate dislocations at a low fluence such as 5×10 17 n/ cm 2 . Computer simulation suggests that this is due to the accumulation of interstitial atoms in the dislocation strain field and also the difficulty of absorption of interstitials to extended dislocation which existed prior to irradiation. Interstitial clusters accumulated along dislocations coagulated to form dislocation loops in Cu and dipole loops which were along 〈1 1 2〉 direction with a 〈1 1 0〉 Burgers vector in Ni. These newly grown loops and dipoles can absorb interstitial clusters due to the unextended nature of these dislocations, and cause disappearance of decoration of interstitial clusters. Dislocations grew to a bow-out shape and was pinned at voids.