Effects of applied strain on nanoscale self-interstitial cluster formation in BCC iron

The effect of applied strains on the configurational evolution of self-interstitial clusters in BCC iron (Fe) is explored with atomistic simulations. A novel cluster configuration is discovered at low temperatures (< 600 K), which consists of < 110 > dumbbells and < 111 > crowdions in a specific configuration, resulting in an immobile defect. The stability and diffusion of this cluster at higher temperatures is explored. In addition, an anisotropy distribution factor of a particular [hkl] interstitial loop within the family of < hkl > loops is calculated as a function of strain. The results show that loop anisotropy is governed by the angle between the stress direction and the orientation of the < 111 > crowdions in the loop, and directly linked to the stress induced preferred nucleation of self-interstitial atoms. (C) 2017 Elsevier B.V. All rights reserved.