In this paper, the Voronoimosaic model and the cohesive element method were used to simulate crack propagation in the microstructure of alumina/graphene composite ceramic tool materials. The effects of graphene characteristic size and volume content on the crack propagation behavior of microstructure model of alumina/graphene composite ceramics under different interfacial bonding strength were studied. When the phase interface is weak, the average energy release rate is the highest as the short diameter of graphene is 10-50 nm and the long diameter is 1600-2000 nm. When the phase interface is strong, the average energy release rate is the highest as the short diameter of graphene is 50-100 nm and the long diameter is 800-1200 nm. When the volume content of graphene is 0.50 vol.%, the average energy release rate reaches the maximum. When the velocity load is 0.005 m s-1, the simulation result is convergent. It is proven that the simulation results are in good agreement with the experimental phenomena.
Keywords: composite ceramic tool material; crack propagation; graphene; toughening mechanism.