Computer Simulation of Fundamental Behaviors of Point Defects, Clusters and Interaction with Dislocations in Fe and Ni

Abstract

In order to investigate the interaction of point defects with a dislocation, an interstitial cluster or a SFT (stacking fault tetrahedron), computer simulation has been carried out in model Fe and Ni crystals. The capture zone (the region where the interaction energy is larger than kT) was determined for various interactions. Calculated capture zone for T =500°C for SIAs (crowdion and dumbbell) around a straight edge dislocation is larger than that for a vacancy in both Fe and Ni. Capture zones for Ni are larger than those for Fe, suggesting that Ni (fcc) has a larger dislocation bias factor than Fe (bcc). Capture zone calculated for an interstitial cluster (dislocation loop) I₆₁ is smaller than that for a straight edge dislocation, especially in Fe. Capture zones were also calculated for an SFT V₂₈ in Ni, indicating a larger capture zone with SIAs (crowdion and dumbbell) and a smaller capture zone with a vacancy.