MWCNT, nano-silica, and nano-clay additives effects on adhesion performance of dissimilar materials bonded joints

Large vehicles, ships, and airplanes are made of hybrid structures with a combination of metal and composite materials. Aluminum and fiber composites are widely used in the aerospace, automotive, and marine industries due to their high strength/weight ratios. In these industries, adhesive joints are preferred as the primary method of forming structural joints. Although the use of adhesives in a combination with different materials provides many advantages over mechanical methods, efforts are being made to increase the strength of the adhesive connection. In this study, three different nanoparticles such as nanosilica, nanoclay, and multiwalled carbon nanotubes (MWCNTs) were added to a commercial epoxy adhesive (Araldite 2014), and the shear strengths of single-lap joints made of aluminum and glass fiber reinforced polymer composite were investigated. According to the experimental results, adding nanoparticles increased the strength of the bonded joints. The best increase was determined as 62% for the connection with 0.5 wt% MWCNTs added. On the other hand, the improvement in the bond with 1.5 wt% nanoclay was found to be 37.8%, while the improvement in the bond with 1.5% nanosilica was 43.3%. Failure types of samples after the mechanical tests were analyzed by taking macro and scanning electron microscopy images from the overlap sides.