This study focused on toughness behavior and mechanical properties of nanoparticles exerted of hot-cured epoxy resins. A comprehensive evaluation was carried out on series of nanocomposites containing varying amounts of nano-sized Al2O3 (nano-alumina) and nanoclay. Tensile strength and young’s modulus of nanocomposite specimens was examined and compared with pure epoxy. Plane strain fracture toughness (KIC) was calculated using single-edge-notch specimens that tested in three point bending condition. Results indicated that fracture toughness improves through increasing both alumina and clay nanoparticle content by several mechanisms. Finally, the fracture surfaces of nanoparticulate-filled epoxy nanocomposite specimens and mechanisms of toughening were observed by using field emission scanning electron microscope.
