The resistance welding of CF/epoxy laminate and 6063Al alloy: morphology, mechanical property and interface evolution

There is an increasing need for joining technologies of resin matrix composites and metals, in which resistance welding is one of the most promising methods. In this work, the resistance welding of 6063Al alloy and CF/epoxy laminate was realized through designing the thermoplastic layer on the surface of the base material. The welding process was conducted under different welding times (t(w)) in this research, while porous stainless steel (SS) mesh was selected as a heating implant. The microstructure of the welding interface formed at different t(w) was characterized by scanning electron microscopy (SEM), and the characteristic area showed a strong correlation with t(w). The results of mechanical strength of the welding joint were obtained by tensile lap shear strength (LSS) test, which indicated that the LSS can reach a maximum value of 19.18 MPa when welding time (t(w)) was 6 mins. To further understand the joint formation process and strength changes law, the evolution process of the welding interface was described in detail according to the temperature distribution simulated by COMSOL. This work provided a technical foundation for large-area surface thermal plasticization in thermosetting composite materials and metals, and then achieve fusion bonding.