FRACTURE-RESISTANCE CHARACTERISTICS OF A METAL-TOUGHENED CERAMIC

The fracture characteristics of an Al2O3/Al composite are examined. Me asurements of resistance curves and work of rupture are compared with predictions of a micromechanical model, incorporating the effects of c rack bridging by the Al reinforcements. The bridging traction law is a ssumed to follow linear softening behavior, characterized by a peak st ress, sigma(c), and a critical stretch-to-failure, u(c). The values of simga(c) and u(c) inferred from such comparisons are found to be broa dly consistent with independent measurements of stretch-to-failure, al ong with the measured flow characteristics of the Al reinforcement. Th e importance of large-scale bridging on the fracture resistance behavi or of this class of composite is also demonstrated through both the ex periments and the simulations.