Improved mechanical performance and unique toughening mechanisms of UDM processed epoxy‐SiO2 nanocomposites

Abstract This work demonstrates improved mechanical performance and unique toughening mechanisms of ultrasonic dual mixing (UDM) processed epoxy‐SiO 2 nanocomposites. The loading of SiO 2 nanoparticles in the epoxy matrix was varied from 1 to 5 vol% to produce the nanocomposites. The mechanical performance was evaluated by measuring the tensile and fracture properties of the nanocomposites. An optimal nanoparticle loading of 3 vol% in epoxy was found vital for improved performance of the nanocomposite. The optimal nanoparticle loading in epoxy lead to an increase of 18.45% in tensile strength and 120% increase in fracture toughness ( G IC ) compared to the neat epoxy. The fracture surface analysis revealed various toughening mechanisms including particle pull out, plastic void growth, plastic deformation, and crack deflection along with a unique mechanism of strong interfacial bonding between SiO 2 particle and epoxy matrix.