A high bonding tensile strength of CFRP ultrafast laser surface texturing method for surface damage repair

Abstract

Carbon fiber reinforced polymer composite (CFRP) has a wide range of applications in aerospace, but it can cause varying degrees of damage in harsh service environments. Seeking a high-performance repair method is an effective way to save costs and ensure the service performance of CFRP components. In this study, a high bonding tensile strength of CFRP surface ultrafast laser texturing method for damage repair was proposed, which achieved complete removal of surface resin while retaining intact exposed fiber filaments. The difference in groove processing under unidirectional scanning and cross-scanning modes at different angles was explored. When the groove spacing was 0.2 mm and 0.4 mm, the surface resin was completely removed, the carbon fiber remained intact, and no debris was inside the groove. The groove morphology has a significant impact on the contact zone of the surface, which in turn affects the mechanical properties of the bonded joint. Cross-scanning can effectively improve surface roughness to increase the contact surface area. However, there is more fiber breakage, manifested as a groove weakening effect, which limits the improvement of bonding strength. In the 0° unidirectional scanning mode, the tensile performance of the joint is the best, improved by 61.6 % compared to manual processing.