Effect of interfacial characteristics on toughness of nanocrystalline cemented carbides

Abstract Dense nanocrystalline cemented carbide bulks were prepared using a unique in situ synthesized WC–Co composite powder with a super-ultrafine nanostructure. Remarkable enhancement in the fracture toughness (with high hardness being maintained) was obtained in the nanocrystalline cemented carbides. Based on detailed studies on the combination of WC and Co phases, the WC/Co orientation relationship and the atomic correspondence at interfaces, the mechanisms for high toughness in the present nanocrystalline cemented carbides were demonstrated. The study proposed that interfacial characteristics play a significant role in the toughness of the nanocrystalline cemented carbides, and provided an effective approach to achieve superior combination properties of hardness and toughness in cermet materials.