Revealing the tunable twinning/detwinning behavior in 25 nm Cu/Au multilayers

Stability of nanotwins during plastic deformation is an important factor to control plasticity of nanotwinned metals. Based on transmission electron microscopy observations of the 25 nm Cu/Au multilayers deformed by indentation, we found that the nanotwins in the Cu and the Au layers have different stabilities through twinning/detwinning. The mechanism-based criterion for the stability of the nanotwins under applied stress proposed here reveals that the tunable twinning/detwinning ability is related to the residual stress in the nanolayered material. The present results may provide a clue for the modulation of plasticity of nanotwinned multilayers through the nanotwin stability. (C) 2013 AIP Publishing LLC.