Zones of spontaneous absorption of point defects by the edge dislocation

Abstract

Vacancy and interstitial interactions with the straight edge dislocation 1 2 [111] (110) in α-Fe have been investigated by a computer simulation method. Zones of spontaneous absorption of point defects by the edge dislocation have been determined. The mean zone radii values were 1.185 nm and 0.340 nm for an interstitial and a vacancy, respectively. The main mechanism of spontaneous absorption has been revealed: the initiation of the replacement chain by the interstitial followed by attachment of the chain's last atom to the dislocation extra half-plane edge. Bond energies of the dislocation with point defects in the absorption zones were about 4 eV and 1 eV for the interstitial and the vacancy, respectively, and significantly higher for those beyond these zones. The effect of interstitial configuration and orientation on the interaction with the dislocation has been evaluated. Application of uniaxial tension to a stress comparable to the flow stress did not affect the sizes of absorption zones. The sizes changed at higher stress levels (5 or 25 times). The relevence of the results to radiation-damage studies is discussed. © 1986.