Interface-facilitated deformation twinning in copper within submicron Ag–Cu multilayered composites

Rolling of Ag–Cu layered eutectic composites with bilayer thicknesses in the submicron regime (∼200–400 nm) activated deformation twinning in Cu. Using atomistic simulations and dislocation theory, we propose that the Ag–Cu interface facilitated deformation twinning in Cu by permitting the transmission of twinning partials from Ag to Cu. In this way, twins in Ag can provide an ample supply of twinning partials to Cu to support and sustain twin growth in Cu during deformation. Interface-driven twinning as revealed by this study suggests the exciting possibility of altering the roles of dislocation slip and twinning through the design of heterophase interface structure and properties.

► Deformation twins in Cu are observed within submicron Ag–Cu multilayers.
► We propose that the Ag–Cu interface facilitated deformation twinning in Cu.
► We demonstrate the proposal using atomistic simulation and dislocation theory.
► Interface-driven twinning suggests the possibility of altering the roles of slip and twinning through the hetero-phase interface design.