Fracture of a brittle composite: influence of elastic mismatch and interfacial bonding

TLDR: In this article, the influence of the presence or absence of elastic mismatch between the dispersed and matrix phases on local crack particle interactions in brittle composites was investigated, and the role of interfacial bond strength was also investigated in the presence of elastic stress concentrations.

Abstract: The influence of the presence or absence of elastic mismatch between the dispersed and matrix phases on local crack particle interactions in brittle composites is reported. The role of interfacial bond strength is also investigated in the presence of elastic stress concentrations. The optimum toughness possible for a brittle composite results when G i⩽G m, (G i, G m — elastic rigidity moduli for inclusion and matrix), and the interfacial bond strength is sufficient to allow plastic deformation of the dispersed phase. The dispersion of a ductile second phase with high interfacial bond strength but G i>G m, reduces effective crack/particle interactions. To increase the toughness in this case, weak interfacial bonding is necessary. Ultrasonic fractography was used to verify the local crack/particle interactions in detail.