Studies on the mechanical and mechanical interfacial properties of carbon-carbon composites impregnated with an oxidation inhibitor

In this work, the relationships between work of adhesion and fracture toughness parameters, such as work of fracture (W_f), the critical stress intensity factor (K_IC), and the specific fracture energy (G_IC), of carbon-carbon composites (C/C composites) were investigated. The impact properties of the composites were also studied in the context of differentiating between the initiation and propagation energies for failure behavior. Composites consisting of different contents of the oxidation inhibitor MoSi₂ displayed an increase of the work of adhesion between the fibers and the matrix, which improved both the fracture toughness and impact properties of the composites. The 12 wt% MoSi₂ composites exhibited the highest mechanical and mechanical interfacial properties. This was probably due to the improvement of the London dispersive component, W _A^L, of the work of adhesion, resulting in an increase in the interfacial adhesion force among the fibers, filler, and matrix in this system.