Mutual reaction between interstitial clusters in bcc Fe

Abstract

Clusters of self-interstitial atoms (SIAs) are commonly observed in microstructure of irradiated metals. These clusters can be formed directly in high-energy displacement cascades or as a result of interaction between individual SIAs. The majority of these clusters has features of glissile dislocation loops and perform fast thermally-activated one-dimensional glide. In this paper we present results of systematic molecular dynamics study of reactions where glissile clusters are involved. On the example of bcc iron we demonstrate that the reactions can result in a number of specific microstructural objects with different properties which may affect the microstructure evolution of irradiated metals. Particularly the reactions between the most common glissile clusters of (111) crowdions can result in coarsening, formation of immobile complexes and change of the crowdion orientation to (100) -type direction. However, particular mechanism responsible for that was found to be different from the one reported in the similar computer simulation studies. Properties of the products of mutual reactions between clusters are quite different which can influence the total microstructure evolution under irradiation. The results are obtained with the most promising interatomic potential for iron.