Fracture surface evaluation of adhesively bonded dissimilar joints reinforced with nanoclay

This study investigates the morphology of fracture surfaces in adhesively bonded dissimilar single lap joints (DSLJs) with dissimilar adherends such as aluminum (Al), copper (CU), stainless steel (SS) and carbon fiber reinforced polymer (CFRP). examining the influence of incorporating nanoclay (NC) at different weight percentages. Tensile testing is conducted on DSLJs (Al-Cu, Al-SS, SS-Cu, and Al-CFRP) to determine the ultimate load. Fracture surface morphology on each adherend is analyzed introducing two surface area parameters. Adding 1.4 wt% NCs to the adhesive enhances epoxy strength by 11% and increases the ultimate load of DSLJs by 29–40%. Moreover, incorporating NCs increased the sensitivity of the adherend (aSurf), and decreased the total failure area parameter (aT), leading to improved adhesion performance and joint strength. A parabolic function depicting the relationship between loading capacity and fracture surface parameters demonstrates a strong correlation. These findings provide valuable insights for DSLJs and can serve as a benchmark derived from fracture surface analysis.