Impact damage in SiO2 nanoparticle enhanced epoxy - Carbon fibre composites

Low velocity impact behaviour of nano-SiO2 enhanced carbon fibre/epoxy composites for naval applications is reported. Epoxy resin matrix was enhanced by 1- 8 wt% SiO2 nanoparticles, based on industrial surface-modified nanosilica. Impact parameters: force, deformation, energy, damage size were recorded. The most pronounced effect was damage size decrease; e.g. ∼28% recorded by infrared thermography and X-ray computed radiography for 8% nano-SiO2 content. Crack branching and crack deflection, due to the nanoparticles, were observed. Decreases in permanent deformation, by ∼15%, and absorbed energy, by ∼8%, were observed, as well as improved fibre/matrix interfacial strength. Flexural strength peaked at 2-5% at ∼640 MPa and then decreased, probably due to nanoparticle agglomerations. There was very little effect of small nanoparticle contents on impact force, deformation and energy, with only a 6% increase of the peak impact force for 8% nano-SiO2 content.