| Carbon nanotubes (CNTs), due to their extremely high mechanical performance, excellent electrical and thermal proper-ties, have been regarded as ideally reinforcement phase of composites. CNTs reinforced metal matrix composites have become a very important research area. However, due to the issues of the compatibility between CNTs and metal matrix, the difficult to control dispersion of reinforcement in spatial and the high ampacity but relatively low conductivity of CNTs, the electric properties of CNTs reinforced metal matrix composites do not show significantly enhancement and the electrical and mechanical properties are difficult to be balanced, the overall research is still in infancy. We dis-cuss the research status of CNTs reinforced metal matrix composites from the aspects of pretreatment, processing method and mechanism of electrical conduction, as well as the outlook for the future development trend in this area.CNTs-Cu composites were respectively fabricated though electrodeposition and powder metallurgy, then the influence of the two method for electrical property were analyzed. According to research in domestic and oversea, electrodeposition that only one method, can achieve high ampacity and high electrical conductivity in CNTs-Cu composite, powder metallurgy was a popular method in fabricate CNTs-Cu composite. Therefore, these two methods are the most representative.The sandwich sample was fabricated by electrodeposition, was measured by four-probe method. The surface morphology, element and phase composition of it were characterized with scanning electron microscopy (SEM), energy Dispersive X-Ray Spectroscopy (EDX) and X-ray diffraction (XRD). The size of coating particle and the morphology of particle which transform spherical into irregular polygon, increases with the electrodeposition current density. Conductivity of sample was decreased to 45.2 × 103 S cm-1 from 2.04 × 103 S cm-1 when current density was increased to 1.0 mA cm-2 from 5.0 mA cm-2. This because compare with spherical and irregular polygon, pore of coatings was less when it was formed by uneven spherical particle. The less pores, the less probability of electron scattering, the more conductivity.Conductivity of sample was fabricated by powder metallurgy was measured by electrical conductivity measurement instrument, the density of sample was measured by Archimedes drainage method. Normal MWCNTs and coated Ni-coated MWCNTs were used in the experiment. Density and conductivity of sample was decreased with increasing capacity of CNTs. Because compatibility of CNTs and Cu was bad, CNTs didn’t react with Cu, the interface of reinforced phase and matrix was bad. Pores was increased with CNTs, the more reinforced phase, the more pores, so density and conductivity was less. On the other hand, conductivity of CNTs is less than Cu, so conductivity of composite was less than Cu. Compare to normal MWCNTs, conductivity and density of sample which fabricated by Ni-coated MWCNTs was better. First of all, Cu and Ni have good compatibility, so the interface of Ni-coated MWCNTs and Cu was better than normal MWCNTs; secondly, degree of dispersion of Ni-coated MWCNTs was better because of Ni and Cu have similar density. In summary, composite which were fabricated by Ni-coated MWCNTs have better properties.
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