Behavior of a self-interstitial-atom type dislocation loop in the periphery of an edge dislocation in BCC-Fe

Abstract

The behavior of the dislocation loop of a self-interstitial atom (SIA) near an edge dislocation and its conservative climb process were modeled in body-centered cubic Fe by incorporating loop rotation. The stable position of the loop and its rotational angle due to the interaction with an edge dislocation were evaluated through molecular dynamics simulations and calculations of the isotropic elasticity. The results were used as input variables in kinetic Monte Carlo simulations to model the absorption of the loop by the dislocation via a conservative climb. Loop rotation was found to affect the velocity of the conservative climb only at short-distances because the gradient in the interaction energy between the dislocation and an atom at the edge of the loop, which is a driving force of the conservative climb, could not be precisely evaluated without loop rotation. Depending on the distance between the dislocation and the loop, allowing the loop rotation resulted in either an increase or decrease in the velocity of the conservative climb.

Keywords

• Conservative climb
• Kinetic monte carlo
• Molecular dynamics
• Elasticity
• Swelling