抄録
Frontal process zone toughening mechanism in particle dispersion ceramic-based composites was clarified based on the energy equilibrium between energy release rate and fracture energy rate (known as Griffith's equilibrium), and local fracture criterion. The results implied that the intrinsic fracture toughness, K_i, of the material measured using a SEVNB technique was proportional to the product of √<r_0> and σ_c, where r_0 represents a critical distance from the crack tip and σ_c is a critical stress at r_0. The relationship between K_i and √<r_0>・σ_c was obtained experimentally for the materials of alumina, silicon nitride, and an isotropic dense graphite.
