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 A degrees 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/cm(3) for green and sintered Cu-5wt% CNT nanocomposites, respectively, while the highest density value was 8 and 8.57 g/cm(3) 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.