Preparation of CNTs/Cu composites with good electrical conductivity and excellent mechanical properties

The uniform dispersion of carbon nanotubes (CNTs) in copper matrix and the formation of strong interfacial bonding between copper matrix and CNTs are two major challenges for the synthesis of the carbon nanotubes/copper (CNTs/Cu) composites. In this paper, the Cu/CNTs and Cu/CNTs-1 composites were successfully prepared by using two different precursor preparation technologies which are alloying method (AM) and co-deposition method (CM), chemical vapor deposition (CVD) and spark plasma sintering (SPS) technique. The results show that the carbon nanotubes prepared by AM have better quality, more homogeneous diameter and higher graphitization degree compared with CM. The mechanical properties of the Cu/CNTs composites (by AM) is improved owing to the strong interfacial bonding and the high load transfer efficiency. The hardness of the Cu/CNTs composites is 102.5 HV, which is increased by 24.7% and 6.5% in contrast with that of pure copper and Cu/CNTs-1 composites (by CM), respectively. And the tensile strength is 275 MPa, which is improved 36.1% and 16.0%. Furthermore, the electrical conductivity of the Cu/CNTs composites keeps at a high level of 92.9%IACS. And the alloying method is simple, feasible, replicable and easy to achieve the goal of the industrial preparation. So this work provides guidance for preparing copper-based composites with good electrical conductivity and excellent mechanical properties.