Laser selective ablated multistep interfacing for enhanced adhesive bonding joints of carbon fiber reinforced polymer materials

Carbon fiber reinforced polymer (CFRP) has been widely used in the aviation field, especially, in the skin structure of civil aircraft. However, the damage is inevitable in service time and the effective repair methods of CFRP are, especially, important. In this paper, a high-efficiency and high-strength multistep interface adhesive structure was designed and prepared by laser selective ablation for CFRP skin maintenance. The micromorphology and surface chemical composition were analyzed under different laser treatment parameters. The tensile shear strength test as well as impact strength test of CFRP multistepped adhesive bonding joints showed that the value of shear strength and impact strength were 86.29 Mpa and 9.43 kJ/m2, respectively, which increased about 11% and 15%, respectively, when compared with the conventional mechanical milling interface. The results showed that the resin matrix between carbon fibers was removed neatly by laser ablation treatment, which lead to the enlarged adhesive contact area and improved comprehensive mechanical properties of the CFRP joints.