Interfacial engineering for high-strength, high-conductivity copper/graphene composites by combined CVD and sputtering

Copper is a fundamental material used in energy and electronic systems. However, achieving a balance between strength and conductivity in existing materials remains challenging, and Joule heating loss under high current restricts the development of high-power equipment. Therefore, it is crucial to develop new copper-based materials with high strength and high conductivity. Graphene is regarded as an ideal reinforcement material for constructing high-performance copper-based composites, owing to its excellent intrinsic properties. In this study, an innovat- ive preparation strategy was proposed: high-quality graphene was grown in situ on copper foil by chemical vapor deposition, and a copper nanofilm was deposited by magnetron sputtering to con- struct a copper/graphene/copper composite sandwich structure, followed by densification via hot- press sintering. The results demonstrated a synergistic improvement in the electrical and mechan- ical properties of the composite: the conductivity reached 105.27% International Annealed Copper Standard, and the tensile strength was 240.32 MPa, both significantly better than those of pure copper. This study confirms that the material properties can be simultaneously optimized through precise interface and structural engineering, providing a new technical approach for developing efficient conductive materials for energy and electronic applications.