On the correlation between self-interstitial cluster diffusivity and irradiation-induced swelling in Fe–Cr alloys

Stability and mobility of small vacancy–solute complexes in Fe–MnNi and dilute Fe–X alloys: A kinetic Monte Carlo study

“…As a matter of fact, solute atoms can be transported by defects towards these nucleation sites, causing the clusters to grow in size. The effective ''pinning effect'' of solute atoms on SIA loops emerges from several studies [6][7][8], whereas the systematic arising of a vacancy drag effect in iron dilute alloys has been recently shown [9] to be a very effective means of solute transport towards defect sinks in RPV steels, and could hence confirm this mechanism. In particular, Mn is expected to have a specifically strong effect on SIA-loop mobility because of the strong interaction between Mn and crowdion, in analogy with the effect of Cr [7] and because it is known to efficiently diffuse via a dumbbell mechanism.…”

Ab initiostudy of solute transition-metal interactions with point defects in bcc Fe

“…When the solute density becomes high enough, the effective range of the traps will start to overlap and the trapping force will decrease again. It was shown, with the support of molecular-dynamics simulations on large simulation boxes, with an alloy cohesive model that closely fits the ab initio data, 16 that this model [7][8][9] of trapping in Fe-Cr reproduced the measured swelling minima at around 9 at. % Cr, assuming that the change in the rate of SIA loop diffusion is the main cause of the concentration dependency of swelling in Fe-Cr.…”

“…A phenomenological model of the interstitial cluster diffusion in Fe-Cr has successfully explained some of the concentration dependency of the swelling under neutron irradiation. [7][8][9][10][11][12] The model used data from ab initio calculations, 13,14 which showed that a single ͗111͘ self-interstitial atom ͑SIA͒ has a strong long-ranged attractive interaction with solute Cr atoms along the line of compression ͑and glide͒. The SIAs in an a / 2͗111͘ loop move independently, dragging the others along after they have moved.…”

Unlimited damage accumulation in metallic materials under cascade-damage conditions

“…higher swelling rates under neutron compared to Frenkel-pair-producing electron irradiation [36,37]; and the absence of void lattices in 1 MeV electron irradiated materials. The framework of the model also accounts for the minimum swelling rate in Fe-Cr alloys at ~10 at% Cr [38] and the absence of copper precipitate growth in Fe-Cu alloys at temperature less than 300°C [39]. The model owes its success to the recognition of two distinguishing features of defect production by high-energy recoils: first, the formation of thermally-stable clusters of self-interstitial atoms (SIAs) directly in displacement cascades, fact revealed both experimentally [40][41][42][43][44] and in molecular dynamics (MD) simulations [45][46][47][48]; and, second, the one-dimensional motion of the SIA clusters [46,[49][50][51][52].…”