A nanostructured Ag/Cu multilayered composite exhibiting high hardness and high electrical conductivity prepared by a novel multicomponent accumulative roll bonding

In the present study, a novel multicomponent accumulative roll bonding (MARB) approach was proposed and successfully applied to prepare a nanostructured Ag/Cu multilayered composite. Microstructure, hardness and conductivity of Ag/Cu multilayered composites with different MARB cycles were investigated by electron backscatter diffraction, transmission electron microscopy, nanoindentation and four-point probe direct current methods. It is demonstrated that the MARB approach is able to effectively suppress the shear band formation and result in a remarkable reduction in the thickness of the Ag/Cu multilayered composite down to 40 nm via only 6 cycles. The as-prepared nanostructured Ag/Cu multilayered composite exhibits an excellent combination of high hardness (2.24 GPa) and high electrical conductivity (equivalent to 84% of international annealed copper standard; IACS). It owes these extraordinary properties to the atomically ordered and chemically sharp heterophase interfaces and low density of grain boundaries resulting from the MARB process.