Femtosecond laser fabricated micro/nano interfacial structures to strengthen CFRPEEK/A6061-T6 FLJ hybrid joints

Metal-thermoplastic hybrid joints have been widely used to lighten weight of advanced flight vehicles in recent years. In the current work, femtosecond laser was used to build double-scale hierarchical structures of microstrip and nanoparticles on A6061-T6 (6061) surface to fabricate stable hybrid joints with carbon fiber reinforced polyetheretherketone (CFRPEEK) by friction lap joining (FLJ). The effects of femtosecond laser modification on bonding strength of CFRPEEK/6061 were uncovered by experimental method and finite element analysis (FEA). The results indicated that the effective mechanical interlocking caused the enhancing bonding strength of CFRPEEK/6061 FLJ joints. Furthermore, by adjusting processing parameters of femtosecond laser modification, 6061 surfaces evolved to be superhydrophobic, resulting in a perfect CFRPEEK/6061 interface without voids and crack, corresponding to the maximal bonding strength of 19.40 MPa.