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.