High Velocity Impact Response of Aluminum- Carbon Fibers-Epoxy Laminated Composites Toughened by Nano Silica and Zirconia.

This research work investigated the effects of SiO₂ and ZrO₂ nanoparticles type and content incorporated into an epoxy matrix on the high velocity impact behavior of carbon fiber reinforced aluminum laminates (CARALL). CARALL specimens consisted of a 0/90/90/0 stacking sequence of a carbon-epoxy composite containing 0, 1, 3, 5 and 7 wt% of each of nanoparticles sandwiched between two layers of aluminum 2024-T3. To observe the toughening effects of the nanoparticles on the fracture surface of the impacted CARALL, a typical field emission scanning electron microscope (FESEM) was employed. Impact energy absorption of CARALL was at most increased by 18 % and 12 % with the nanoparticles content of 5 wt% SiO₂ and 3 wt% ZrO₂, respectively. Overloading of the nanoparticles content up to 7 wt% resulted in the creation of nanoparticles aggregated sites associated with loss in the energy absorption capacity. FESEM fractography procedure also showed that the crack deflection and pinning were the most recognizable toughening mechanisms exhibited by nanoparticles. Overall, the controlled addition of SiO₂/ZrO₂ rigid nanoparticles to CARALL was found to be a promising method for improving the high velocity impact energy absorption of CARALL. [ABSTRACT FROM AUTHOR]