Influence of Features of Interphase Boundaries on Mechanical Properties and Fracture Pattern in Metal-Ceramic Composites

The results of a theoretical study on the influence of strength of interphase boundaries in metal-ceramic composite on macroscopical characteristics of composite response such as strength, deformation capacity, fracture energy and fracture pattern are presented. The study was conducted by means of computer- aided simulation by means of movable cellular automaton method taking account of a developed mesoscopical structural model of particle- reinforced composite. The strength of interphase boundaries is found to be a key structural factor determining not only the strength properties of metaleceramic composite, but also the pattern and rate of fracture. The principles for achievement of the high- strength values of particle/ binder interfaces in the metaleceramic composition due to the formation of the wide transition zones (areas of variable chemical composition) at the interphase boundaries are discussed. Simulation results confirm that such transition zones provide a change in fracture mechanism and make the achievement of a high- strength and a high deformation capacity of metal-ceramic composite possible.