The flexural and impact behavior of the laminated aluminum-epoxy/basalt fibers composites containing nanoclay: An experimental investigation

In this study, the effect of different weight percents of modified/unmodified nanoclay particles on the flexural and impact properties of fiber–metal laminates made of 2024-T3 aluminum sheets and basalt fibers as the reinforcements and epoxy as the matrix was investigated. As a first step, the surface of nanoclay particles was modified by the silane-coupling agent. The creation of the functional groups on the surface of nanoclay particles was confirmed by Fourier transform infrared spectroscopy analyses. The modified nanoclay with different weight percents of 0, 1, 3, and 5 was added into the epoxy matrix; then, for the better distribution and dispersion of nanoparticles in the matrix, the mechanical and ultra-sonication machines were used. Also, to ensure better interaction and adherence between the matrix and the aluminum sheets, the mechanical and chemical treatments were conducted. Then, the mixture of epoxy and nanoclay with woven basalt fibers and aluminum sheets was used to fabricate fiber–metal laminates. To survey the effect of these nanoparticles on the mechanical properties, the three-point bending test and the high-velocity impact test were used. The results showed that the maximum effect of adding nanoclay particles on the flexural and impact behavior was obtained by using 3 wt.% of the modified nanoclay. These properties of fiber–metal laminates, which contained the 3 wt.% unmodified nanoclay, were weakened in comparison to a similar specimen containing the modified nanoclay. Furthermore, the flexural modulus was enhanced by increasing the weight percent of the nanoparticles. Also, to investigate the fracture mechanism, the field emission scanning electron microscope was used. The microscopic images revealed that adding nanoclay particles led to the improvement of the interaction between the matrix and basalt fibers, thereby improving the flexural and impact properties.