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. [Display omitted] •A novel severe plastic deforming process named MARB was proposed.•MARB approach regulated the geometry of the rolling gap to effectively suppress the shear band formation.•MARB approach was able to significantly improve the efficiency of layer refinement.