Fracture toughness measurement of WC-Co hardmetals by indentation method

Well defined crack configuration generated by a complex fracture patterns produced by Vickers Indenter provided basis for working out an improved method of indentation fracture toughness measurement. The effect of the indenting load, the preparation of the specimen surface and remaining residual macrostresses on the indentation fracture toughness has been observed. Using a high sensitivity moire interferometry method a quantity analysis of the displacements and strains field in out-of-plane w (x,y) and in-plane v (x,y) around the hardness indent near the Palmqvist (radial) cracks was carried out.