It was recalled that, in Cu and other face-centered cubic metals, high-energy particle bombardment produced hardening and shear localization. Post-irradiation microstructural examination of Cu revealed that irradiation had produced a high number density of nm-sized stacking-fault tetrahedra. The resultant irradiation hardening and shear localization was normally attributed to interactions between stacking fault tetrahedra and mobile dislocations; although the interaction mechanism was unknown. A molecular dynamics simulation study was used to characterize the motion and velocity of edge dislocations at high strain rates, and the interaction and fate of moving edge dislocation with stacking fault tetrahedral, by using an EAM interatomic potential. The results showed that a perfect stacking fault tetrahedron acted as a hard obstacle to dislocation motion and, although the stacking fault tetrahedron was sheared by passage of the dislocation, it remained largely intact. The simulations also showed that an overlapping truncated stacking fault tetrahedron was absorbed by the passage of an edge dislocation; thus resulting in dislocation climb and in the formation of a pair of less-mobile super-jogs on the dislocation.

Dislocation-Stacking Fault Tetrahedron Interactions in Cu. B.D.Wirth, V.V.Bulatov, T.Diaz de la Rubia: Journal of Engineering Materials and Technology, 2002, 124[3], 329-34