Influence of interfacial strength on the fracture toughness of glass-ceramic matrix composites

Nine kinds of glass-ceramic matrix composites with different compositions and interfacial strength (τs) were prepared. The influence of τs on the fracture toughness(K1c) of composites was studied. It was discoved that, for the system no chemical reaction taking place at the interface, K1c increased proportionally with τs increasing at the first stage, then decreased when τs reached a certain value. According to this result, a model of relationship between τs, thermal mismatch (Δαr) and K1c was built up. If a chemical reaction took place and a new phase was formed in the interface, the K1c of composite was effected by the combination of τs, chemical bonding, radial interfacial stress and other factors.