Detecting co-deformation behavior of Cu-Au nanolayered composites

Co-deformation behavior is a key issue for plasticity stability of heterogeneous nanolayered materials. Using indentation testing, we investigated the plastic deformation behavior of a Cu-Au nanolayered composite (NLC) with an individual layer thickness of 50 nm. We found that the softer Au layer exhibited less deformability than the harder Cu layer in the initial stage of deformation, while this abnormal phenomenon started to gradually disappear as the constituent layers were severely thinned down to thicknesses less than about 10 nm. The basic mechanism for the observed co-deformation behavior at different length scales of the Cu-Au NLC will be discussed. [GRAPHICS] IMPACT STATEMENT An abnormal phenomenon of reduced deformability of Au layers compared to Cu layers in Cu-Au NLCs gradually disappeared as the constituent layer thicknesses were thinned plastically to less than 10 nm.