Influence of Particle Size Distribution on Ductile-Phase Toughening in Brittle Materials

In ductile-phase-toughened brittle materials the size distribution of the ductile phase sometimes has a remarkable effect on toughening. An equation for predicting the toughness increment due to crack bridging, taking into account a ductile-phase particle size distribution, has been deduced. Comparison between the toughness value predicted by the equation and that obtained from a double cantilever beam (DCB) method on a Al2O3–20 vol% Ni composite material has shown that the equation gives a more reasonable estimate of the toughness than previous equations.