The fracture behaviour of nanostructure added adhesives under ambient temperature and thermal cyclic conditions

In this study, the fracture behavior of nanocomposite adhesives produced by adding nanostructure in to the adhesives were investigated using Double Cantilever Beam (DCB) test under ambient temperature and thermal cycle conditions. Adhesively bonded DCB joints were produced using DP460 toughened adhesive type and DP125 flexible adhesive type as the adhesives; AA2024-T3 aluminum alloy was used as the adherend, and 1 wt.% Graphene-COOH, Carbon Nanotube-COOH and Fullerene C60 were used as the added nanostructures. As a result, when the experimental fracture energy was examined, the nanocomposite adhesives obtained by adding nanostructure were found to have increased the fracture energy of the joint. In the joints bonded with the flexible DP125 adhesive that were subjected to thermal cycles, the addition of Graphene-COOH into the adhesive increases the fracture energy of the joint by 55%, the addition of Fullerene increases the fracture energy of the joint by 135%. Also, it was observed that there is a significant difference between the displacements that were obtained directly from the test machines stroke and measured via video extensometer giving the crack opening between the top and bottom adherends during the DCB test. This situation significantly effects the correct calculation of the fracture energy of adhesive. © 2018 Elsevier Ltd