Processing and properties of carbon nanotubes-nano-WC-Co composites

Carbon nanotubes-nano-WC-Co composites were prepared by spark plasma sintering process. The preparation steps involving purified carbon nanotubes were stirred into the nano-WC-Co particles in alcohol using ultrasonic shaker, then ball milled for 60 min. The densification and grain growth behavior, the mechanical properties of the nanocomposites were investigated. Experimental results show that with small amount of carbon nanotube additions, the density of the composites can be enhanced but the grain size has marginal increase; the sintered nanocomposites combine superior hardness to toughness relationships over that of the pure nanocrystalline WC-Co cermets fabricated under the same process. The reasons for the increments can be due to the extraordinary mechanical properties of carbon nanotubes, the toughing and bonding role of carbon nanotubes occurred in the nano-WC-Co matrix, as well as the spark plasma sintering technique used. (C) 2004 Elsevier B.V. All rights reserved.