Microstructure and Microhardness of Carbon Nanotube-Silicon Carbide/Copper Hybrid Nanocomposite Developed by Powder Metallurgy

The main objective is to enhance the mechanical properties of copper without losing their inherent electrical conductivity. This paper reports on the effect of Multiwalled Carbon Nanotubes (MWCNTs) and Silicon Carbide (SiC) reinforcement addition on microstructure, microhardness and electrical properties of copper-based hybrid nanocomposite. Hybrid nanocomposites have been synthesised by powder metallurgy technique which involves blending of composite powder, compaction, sintering followed by hot pressing. Microstructural characterizations of prepared hybrid nanocomposites were carried out using optical and Scanning Electron Microscope (SEM). Developed nanocomposites were also subjected to density measurement, microhardness test and electrical conductivity studies. Optical and SEM images reveal that SiC particles and MWCNTs were dispersed uniformly within the copper matrix. The densities of nanocomposites were significantly reduced owing to low densities of MWCNTs and SiC. An improvement in hardness of about 1.5 times has been observed for nanocomposites when compared with pure copper prepared under similar conditions. However, reduction in electrical conductivity of nanocomposites was observed due to grain refinement caused by multiple reinforcements and porosity. The developed hybrid nanocomposites have the potential as material candidates for self-lubricating bearings and bushes.