Effect of the Reinforcement Phase on the Electrical and Mechanical Properties of Cu-SWCNTs Nanocomposites for Potential Application on Conductors Wires

Abstract

In this research a pre-treatment of single-walled carbon nanotubes (SWCNTs) was performed to obtain Cu-SWCNTs composites by combination of electroless deposition and powder metallurgy technique. Previously, the SWCNTs were subjected to a chemical functionalization in acid medium and coated with metallic copper to improve their incorporation into the metal matrix. The results revealed a suitable inclusion of carboxyl, carbonyl and hydroxyl groups in the nanotubes, maintaining their structural integrity. On the other hand, electroless process allowed a complete reduction of copper sulfate to a metallic copper and then a suitable carbon nanotubes incorporation into the matrix. Microhardness measurements presented an improvement of 13% compared with pure copper and, a good wear resistance (2.1x10-4 mm3/Nm) in the sample that reached the best hardness performance was observed. An increase of the wear rate with the concentration of nanotubes can also be seen, which could be related to the high porosity in this samples. Finally, the maximum electrical conductivity reached was 96% IACS in the samples with the least amount of SWCNTs which confirms their excellent dispersion into the copper matrix. Furthermore, the decrease of conductivity with high content of nanotubes (>0.1 weight%) could also be attributed to increase of nanocarbon agglomeration and porosity which acting as insulation barriers. Figure 1