The Impact of Graphene Oxide Nano-fillers on the Bonding Strength and Delamination in Deep Drawing of FMLs

Fiber-metal laminates (FMLs) are rapidly advancing materials that combine the characteristics of resin-based composites and metals. These properties can be further enhanced by incorporating nanoscale particles, resulting in a variant known as FMLs-Nano. This study explores the mechanical properties of FMLs with the incorporation of Graphene Oxide (GO) and investigates for the first time the influence of GO on bonding strength, aiming to improve the laminate's performance during the forming operation by eliminating delamination defects. The goal is to expand the potential applications of FMLs-Nano and enable the production of intricate components. To evaluate the influence of GO, we conducted tests on several mechanical aspects, including tensile strength, flexural performance, and lap shear strength. These tests involved using different GO fractions in the laminate. Microscopy was employed to examine damage patterns and understand failure behavior. Additionally, deep drawing experiments were performed and compared with conventional FMLs to evaluate the GO influence on delamination failure. The results indicate that FML-GO exhibits superior tensile performance compared to conventional FMLs, with FML-GO tensile strength and Young's modulus improved by 11.7% and 13.5%, respectively. Moreover, flexural and interface shear strength showed remarkable improvements, with an increase of 134% and 150% compared to conventional FMLs. These improvements were verified through mechanical testing and further confirmed by scanning electron microscope observations. Additionally, deep drawing experiments demonstrated significant improvement as delamination of the FML layers was successfully eliminated during the forming process.