Comparison of the effects of femtosecond and nanosecond laser tailoring on the bonding performance of the heterojunction between PEEK/CFRP and Al-Li alloy

In this paper, an ultrafast femtosecond laser was used to tailor the surface of the PEEK/CFRP (carbon fiber reinforced plastics with polyether ether ketone as resin matrix), using a nanosecond laser as a contrast. By analyzing the effect of femtosecond and nanosecond laser tailoring on the surface morphology, surface chemical composition and wettability of PEEK/CFRP, the internal reasons for the improved of bonding performance of heterojunction between PEEK/CFRP and Al-Li alloy by laser pretreatment were explored. As a result, the shear strength increased considerably from 4.9 MPa to 16.1 MPa and 29.5 MPa after nanosecond laser and femtosecond laser pretreatment, respectively. Finally, the fracture surface and failure modes of heterojunction bonded joints were compared, and the different mechanisms of femtosecond and nanosecond laser tailoring PEEK/CFRP surface were explained. Femtosecond laser tailoring is a competitive process for improving the bonding properties of the heterojunction between PEEK/CFRP and Al-Li alloys because of its productivity, controllability and lack of pollution.