Kinetic effect on the interaction between edge dislocations and stacking fault tetrahedra in FCC crystals
Abstract
<p indent="0mm">This study investigates the interaction between an edge dislocation and an array of irradiated stacking fault tetrahedra (SFT) in face-centered cubic (FCC) Cu and Ag crystals using molecular dynamics/statics simulations and theoretical analysis. This study primarily aims to understand the kinetic inertia effect on the mechanisms of dislocation-SFT interaction and the critical resolved shear stress (CRSS) for the dislocation bypassing the SFT (i.e., the SFT strength). The results reveal at least five distinct dislocation-SFT interaction mechanisms (M1–M5). When the dislocation slip plane is located at a far enough distance away from the SFT base, the dislocation tends to directly cut through the SFT via the M1/M2 mechanisms. Conversely, if the dislocation slip plane is close enough to the SFT base plane, the dislocation opts to climb over the SFTs via the M3–M5 mechanisms. The change in CRSS for dislocations bypassing the SFTs relative to the size of the slip plane-SFT intersection displays a two-stage response when the dislocation-SFT interaction mechanisms transition. Although the kinetic effect of dislocation motion has a minimal impact on the dislocation-SFT interaction mechanism, it considerably decreases the CRSS for dislocations bypassing the SFTs. Therefore, a two-stage theoretical model of SFT-hardening behavior was developed, taking into account both the kinetic inertia effect and the transition of dislocation-SFT interaction mechanisms.</p>
