Simultaneously enhancing the mechanical and electrical properties in CNTs/Cu composites via chemical vapor deposition introducing ex-situ interfacial WC

In this work, nano-scale WC interface phase was pr-introduced on the surface of CNTs (WC@CNTs) by chemical vapor deposition using CH4 as C source and ammonium metatungstate served as the W source. Subsequently, the WC@CNTs reinforced copper matrix composites (WC@CNTs/Cu) were prepared by spark plasma sintering (SPS). The effect of WC on the mechanical and electrical properties of the composites was studied in detail. The formed “CNTs-WC-Cu” interface not only guarantees accurate stress/strain transmission, but also enhances the interfacial conductivity by reducing interfacial scattering, which contributes to the considerable mechanical and electrical properties of WC@CNTs/Cu over CNTs/Cu. It was found that the interface of “CNTs-WC-Cu” formed by WC can not only effectively transfer the stress, but also improve the interfacial conductivity by reducing the interfacial inelastic scattering, making WC@CNTs/Cu composites exhibit excellent mechanical and electrical properties. When the addition of CNTs was 1% vol%, the ultimate tensile strength of WC@CNTs/Cu composite reached 302 MPa, which was 34.2% and 41.1% higher than that of CNTs/Cu composite and pure Cu, respectively, while maintaining an excellent fracture elongation of 27%. Additionally, the WC@CNTs/Cu composite exhibits an electrical conductivity of 94.4 %IACS, which is comparable to that of pure Cu prepared by the same method.