The dislocation plasticity of Au/Cu multi-layer of 100nm in scale was investigated by means of 3-point bending tests. It was found directly that clear slip lines appeared within the grains, ranging from 60 to 190nm. The finding implied that dislocation plasticity was still the predominant deformation mechanism in the material. Statistical evaluation of the mean spacing between slip-lines revealed the effect of the length-scale upon the homogeneity of plastic deformation. The critical length-scale for dislocation-dominated deformation of the nanoscale material was found to be ~15nm.

Direct Observation of Dislocation Plasticity in 100nm Scale Au/Cu Multilayers. Y.P.Li, G.P.Zhang, J.Tan, B.Wu: Applied Physics Letters, 2007, 91[6], 061912