TEMPERATURE EFFECT ON THE MECHANICAL-BEHAVIOR OF WC-CO CEMENTED CARBIDES

This work is based on a study of the mechanical behaviour of four WC-C o cemented carbides grades at high temperature. The tests, carried out in four point bending, have allowed to establish the variations of fr acture stress, elastic limit and elastic modulus versus temperature. A ll these properties decrease regularly as the temperature increases. W eibull's modulus has been determined at 600 and 800 degrees C. The eff ects of: processing defects, cobalt content and temperature, on the sc attering values of fracture stress have been discussed. An exponential expression is adjusted to the E=f(T) curves taking into account volum ic cobalt fraction, temperature, activation energy of Co and WC/Co int erface, and the porosity.