Interfacial and twin boundary structures of nanostructured Cu-Ag filamentary composites

A high-resolution transmission electron microscope was used to study the interfacial and twin boundary structure of nanostructured Cu-Ag filamentary composites. Copper matrix and silver filaments have the orientation relationship {111} (Cu)\\{111}(Ag) and <111>(Cu)\\<111>(Ag). In some regions, twin bands propagated through the silver filaments with some boundary steps at the matrix/filament interface, and the silver filament appeared to be kinked in the twin band in the same direction as the twinning shear. This suggests that twins propagated after the formation of silver filament, and twin bands were deformation twins. At the matrix/filament interface, misfit interface dislocations were introduced periodically to relieve the misfit strain. The distance between interfacial misfit dislocations along the matrix/filament interface in the longitudinal section was measured to be 1.88 nm, which is in good agreement with that (1.81 nm) calculated based on lattice misfit. In Cu-Ag nanocomposites, the spacing between Moire fringes was found to be quite close to that between interfacial misfit dislocations.