Fracture of WC-Ni cemented carbides with different shape of WC crystals

The dependences of fracture toughness and crack propagation on the shape equiaxiality of WC crystals are studied on WC-Ni cemented carbides with small addition of TiC. The fracture toughness K-1C linearly correlates to mean linear path in binder phase regardless of the shape and contiguity of WC crystals as well as despite of the fracture path change in studied WC-Ni cemented carbides. It is experimentally shown that the fracture toughness K-1C does not correlate versus contiguity of carbide crystals on WC-Ni cemented carbides when shape of WC crystals is changed. The relative amount of trans-crystalline fracture through the carbide crystals and the total area of fracture through the carbide phase increase, whereas, the relative amount of inter-crystalline fracture along carbide-carbide boundaries decrease on WC-Ni cemented carbides with flatter WC crystals and lower values of contiguity of WC crystals. (C) 2007 Elsevier Ltd. All rights reserved.