Abnormally high strength and low electrical resistivity of the deformed Cu/Mg-composite with a big number of Mg-filaments

Cu/Mg-composites, the copper matrix of which contains 1, 7 and 2730 magnesium filaments, were obtained by hyrdoextrusion at room temperature. The structure, mechanical and electrical properties of the deformed composite rods and thin wires were investigated. The yield strength and electrical resistivity were theoretically calculated and these estimations were compared with the experimental results. The XRD-method allowed discovering a change of the lattice constant of the Cu-matrix under deformation of the composites. It has been concluded that, under severe plastic deformation, a supersaturated Cu-based solid solution forms on the Cu/Mg-interface. As a result, the strength of the deformed Cu/Mg-composite with minimal volume fraction but maximal surface area of magnesium is abnormally high. A thick Cu-sleeve provides low electrical resistivity of this Cu/Mg-composite. The obtained results can be used for the development of high-strength Cu-based conductors. © 2019 The Authors Ural Branch, Russian Academy of Sciences, UB RAS The work was carried out in the framework of a state task according to the theme ?Pressure? No. AAAA-A18-118020190104-3. The studies of structure and mechanical properties of the samples were carried out at the Electron Microscopy Department and Mechanical Test Department of the Collective-Use Center of the Institute of Metal Physics (Ural Branch, Russian Academy of Sciences). The X-ray diffraction studies were carried out in the ?Composition of Compounds? Center of Collaborative Access, Institute of High-Temperature Electrochemistry, Ural Branch, Russian Academy of Sciences.