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 K1C 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 K1C 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.