Friction and wear characteristics of copper nanocomposites reinforced with uncoated and nickel coated carbon nanotubes

In the present work we report the development of carbon nanotube having multi-walls reinforced copper nanocomposites. The carbon nanotubes were used in both uncoated and nickel coated conditions to reinforce copper matrix. The nanocomposites with different carbon nanotubes (0.25 to 1.0) weight percentage were developed using a combination of ultrasonication, ball milling, sintering and upsetting forging processes. The developed nanocomposites were subjected to microstructural characterization using scanning and transmission electron microscopes to observe the dispersion of carbon nanotubes. The effect of carbon nanotubes on friction and wear properties of copper nanocomposites were studied using pin on disc testing rig as per ASTM G99 standard. The coefficient of friction of both 1 wt% uncoated and nickel coated carbon nanotubes reinforced nanocomposites was found to drop by 60.41% and 70.83% respectively when compared to copper. Similarly the wear rate of nanocomposites were found to decrease with the incoporation of carbon nanotubes. The low coefficient of friction and wear rate were attributed to uniform dispersion of carbon nanotubes and formation of carbonaceous layer on the surface of nanocomposites during dry sliding wear. (paper)