Electric-discharge compaction of graded WC-Co composites

Electric-discharge compaction (EDC) of nanocrystalline and coarse WC-Co powders to produce graded WC-Co cemented carbides was conducted in this work. Coarse and ultrafine graded WC-Co cemented carbides which offer high hardness and excellent fracture toughness was produced simply by EDC; the microstructure and mechanical properties of graded materials are also investigated. As a consequence of the short holding time in EDC, cobalt migration which always occurred in graded WC-Co during liquid phase sintering process due to the difference in WC grain sizes was kinetically constrained in the present study. It may offer a novel simple processing route to fabricate graded materials. (C) 2007 Elsevier Ltd. All rights reserved.