Novel synthesizing and characterization of copper matrix composites reinforced with carbon nanotubes

In this study, we synthesized a novel copper matrix composites reinforced with carbon nanotubes (CNTs/Cu) by combination use of the electroless deposition (ED) and spark plasma sintering (SPS) methods. Firstly, a uniform copper layer was coated on the surface of carbon nanotubes (CNTs), then the CNTs/Cu composite powders containing different volume fractions of CNTs were obtained by mixing copper powder and copper coated CNTs. Finally, the CNTs/Cu composites were rapidly consolidated via SPS process. The powders and sintered composites were characterized using X-Ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Mechanical properties, Vickers hardness, and electrical conductivity of the CNTs/Cu composites were measured. The results indicated that the mechanical properties of CNTs/Cu composites were obviously improved due to the homogeneous dispersion of CNTs in the copper matrix and the formation of strong chemically bonded interfaces between CNTs and matrix. The CNTs/Cu composite containing 0.5 vol% CNTs has a maximum Vickers hardness of 1.3 GPa and highest yield strength of 142.2 MPa (which is increased by 150% compared with that of pure copper). In addition, the electrical conductivity of the composite was maintained at a high level of 90.9%IACS (International Annealed Copper Standard).