Mechanism of bonding of AA7075 aluminum alloy and CFRP during friction assisted joining

This work investigates the mechanism of bonding and the influence of the process parameters during Friction Assisted Joining of aluminum alloy AA7075 with carbon fiber reinforced PolyPhenylene Sulfide. Laser texturing was performed on the aluminum surface to promote mechanical interlocking between the metal and reinforced plastic substrates. The influence of the tool rotation speed, the plunging force, the plunging speed, and the texturing strategy on the quality of the joints was determined. The results indicated the feasibility of the process when texturized substrates were used. The mechanism of bonding was based on the mechanical interlocking between the aluminum texture and the ejected polymer matrix. Indeed, poor interaction between the texture and carbon fiber was observed regardless of the processing conditions involved. Nevertheless, the joints were characterized by high load-bearing capability (up to 10.7 kN). Besides, the process involved a short joining time (even 1 s) and required relatively low joining forces (almost 800 N).