Recent theoretical calculations and atomistic computer simulations had shown that glissile clusters of self-interstitial atoms played an important role in the evolution of microstructure in metals and alloys under cascade damage conditions. Over the past decade or so, the properties of self-interstitial atom clusters in face-centered cubic, body-centered cubic and hexagonal close-packed lattices had been widely studied. Key properties of these defects and also those of vacancy clusters formed directly in cascades were reviewed here, and an atomic-level picture was presented, based upon computer modelling, of how these properties may change in the presence of other defects, impurities, stress fields, etc. The role of cluster properties and the consequences of their interactions in the process of damage accumulation and changes in mechanical and physical properties was then examined. Attention was focussed on the formation of defect clusters (e.g. dislocation loops and stacking fault tetrahedra) and their segregation in the form of rafts of dislocation loops and atmospheres of loops decorating dislocations. Finally, the problem of radiation hardening was addressed by considering interactions between mobile dislocations and defect clusters (e.g. self-interstitial atom dislocation loops, stacking fault tetrahedra and micro-voids) produced during irradiation.

Atomistic Study of the Generation, Interaction, Accumulation and Annihilation of Cascade-Induced Defect Clusters. Y.N.Osetsky, D.J.Bacon, B.N.Singh, B.Wirth: Journal of Nuclear Materials, 2002, 307-311[2], 852-61