Brittle fracture of cracked solids as affected by surfactants

The comparative study of breaking cracked solids, with or without a surfactant in a crack, is in progress. Chemically intensified fracture as well as the fracture retardation due to formation of new force bonds at the crack tip are considered. Experiments with breaking chromite (FeCr2O4) have been performed in a planetary mill. Solid-phase additives measuring about 4% of chromite by weight are used for surfactants. Estimates for the critical stress intensity factor (SIF) and the critical length for cracks of opening mode are obtained. For considered cases the critical crack lengths, as a rule, differ by one order. The critical values of loading for fixed crack lengths for these cases differ markedly.