The energy absorption behavior of hybrid composite laminates containing nano-fillers under ballistic impact

Abstract

Hybrid composite laminates consisting of woven Kevlar fiber fabric, epoxy and AA 5086-H32 aluminum sheets were produced and the effects of addition of micro and nano-fillers to the fiber on ballistic response of the hybrid laminates were investigated. The micro and nano-fillers used in this study are powders of aluminum, gamma alumina, silicon carbide, colloidal silica and potato flour. They were introduced into the Kevlar fabrics by mixing with polyethylene glycol (PEG-400), followed by impregnation of the Kevlar fabric with the mixture and drying to eliminate the solvent. The energy absorption by the hybrid composite laminates containing the various nano-fillers under ballistic impact were determined and compared with laminate containing no nano-filler impregnation. The ballistic impact resistance of the produced hybrid composite laminates was tested according to NATO standards using a caliber 270 Winchester rifle. The projectile penetration and the resulting perforations of the hybrid laminates were studied in order to determine the influence of the deposited nano-fillers on Kevlar fibers on their energy absorption and impact resistance. The relationship between areal density and energy absorbed are discussed to determine which specimens perform better under ballistic impact. Protection levels achieved by targets were analyzed in relation to the initial impact energy from low caliber weapons. The results indicate that the ballistic impact resistance and impact energy absorption of the hybrid composite laminates were enhanced by deposition of micro and nano-fillers into surface of the Kevlar fibers fabrics. The highest impact energy absorption capacity was achieved by deposition of aluminum powder followed be colloidal silica and silicon carbide powder in that order. Addition of gamma alumina powder and potato flour has produced the least effect of enhancing the impact energy absorption capability of the laminates. These findings indicate that introduction of micro- and nano-fillers coating on Kevlar fabrics using PEG-400 is a promising method for strengthening interfacial bonding between the matrix and fibers in hybrid composite laminates.