Comparative study of infrared laser surface treatment and ultraviolet laser surface treatment of CFRP laminates

Adhesive bonding technique for carbon fiber reinforced plastics (CFRP) composites is believed to be a promising connection method in terms of aircraft composite structural components. The laser surface cleaning processing is an effective way to improve the mechanical properties of CFRP adhesive bonding joints. The comparison between infrared laser surface treatment and ultraviolet (UV) laser surface treatment of CFRP laminates is investigated with various laser processing parameters. The microstructure characteristics and energy dispersive spectroscopy (EDS) results are analyzed. In addition, the detections of bonding strength and contact angles are also performed. The results indicate that the infrared laser thermal effect leads to the burning of carbon fibers, while UV laser surface processing with no thermal effect guarantees the integrity of fibers. Compared with infrared laser processing, the adhesive bonding joints obtained by UV laser treatment have a higher average shear strength.