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.
维普
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