Dislocation decoration and raft formation in irradiated materials

Heavy-ion irradiations of Fe and Fe–Cr model alloys Part 2: Damage evolution in thin-foils at higher doses

“…In the videos bright dots often appeared at the peripheries of large loops, then faded, suggesting absorption onto the dislocation line causing climb. Again this is consistent with the simulations of Wen et al [15]. In their study of dislocation decoration they find that small clusters are often trapped near the cores of line dislocations, where they can reorient their Burgers vectors to become parallel to that of the line dislocation and finally be absorbed.…”

“…[12][13][14]. Raft formation in irradiated materials has been discussed recently by Wen et al [15]. These authors found in Kinetic Monte Carlo simulations that raft formation can be achieved by the prismatic glide of one-dimensional (1-D) interstitial clusters and rotation of their Burgers vectors under the influence of internal strain fields.…”

“…Loops form at the sites of loop clusters or strings, and both the resolvable loops and the loop strings have ½ <111> Burgers vectors. Wen et al [15] find that groups of 5 or more loops are immobile and it seems reasonable to suppose that these strings act as the nuclei for large interstitial loops. The loops in the string would be expected to climb and coalesce by a similar mechanism seen for the larger loops as they develop into finger loops, as described below.…”

“…These authors found in Kinetic Monte Carlo simulations that raft formation can be achieved by the prismatic glide of one-dimensional (1-D) interstitial clusters and rotation of their Burgers vectors under the influence of internal strain fields. We quote from Wen et al [15]…”

Multiscale Materials Modeling of Structural Materials for Next Generation Nuclear Reactors

“…Dislocation-defect interactions may be associated with defects in the matrix, the modification of the local elastic constants due to the presence of defects and defect clusters and the effects of clusters and voids on the stacking fault energy. The formation of self interstitial loop rafts and the decoration of dislocations with self interstitial clusters have become important issues for understanding radiation hardening and embrittlement under cascade damage conditions (Wen, Ghoniem et al 2005). Dislocation motion is thought to be the main mechanism for deformation, because a fairly high density of network dislocations are generated during irradiation, and the dislocation sink strength for point defects is much higher that the grain boundary sink strength for point defects.…”