Effect of the CNT Content on Microstructure, Physical and Mechanical Properties of Cu-Based Electrical Contact Materials Produced by Flake Powder Metallurgy

In this study, Cu matrix nanocomposites with reinforced CNT particles (0.5–5 wt %) were successfully fabricated by employing flake powder metallurgy with warm-pressing and sintering technology at 950 °C for 2 h. The properties of the composite powders were analyzed using a hall flowmeter for the apparent density, a laser particle size analyzer for the particle size and a scanning electron microscopy for the powder morphology. The green and sintered density, hardness and electrical conductivity of Cu–CNT contact materials were determined utilizing Archimedes method, a hardness analyzer and an electrical conductivity measurement device, respectively. The results showed that both consolidation ability and electrical conductivity of the Cu–CNT nanocomposites decreased by increasing the CNT content. The lowest density was 6.3 and 6.73 g/cm3 for green and sintered Cu–5wt% CNT nanocomposites, respectively, while the highest density value was 8 and 8.57 g/cm3 for green and sintered Cu–0.5wt% CNT nanocomposites, respectively. The measured conductivity values were 74.56 IACs for 0.5 wt% CNT- reinforced sintered samples and decreased up to 46.3 for 2 wt% CNT-reinforced sintered samples and then decreased to 5.3 IACs for 5 wt% CNT-reinforced sintered samples.