Creating short aramid fiber/epoxy (SAFE) bonding layer on aluminum alloy to improve the adhesive joint with carbon fiber reinforced polymer

This study focused on bonding strength improvement between aluminum alloy and carbon fiber reinforced polymer (CFRP) composite. Laser engraving method was used to create grooves on surface of aluminum substrate, and resin pre-coating (RPC) was used to disperse high-viscosity resin into resin pre-coating solution to be introduced into pre-fabricated structure, which contributed to reducing bonding defects and constructing short aramid fiber/epoxy (SAFE) bonding layer after full evaporation of acetone to improve mechanical interlocking. The results showed bonding strength of composite with engraving space of 0.2 mm and RPC with short aramid fibers was 20.32 MPa, 220.4 % higher than the base. The failure mode was changed from debonding failure on aluminum surface to delamination failure of CFRP. The research confirmed laser engraving and RPC as simple and effective combined methods on improving bonding strength of aluminum-CFRP composites, which could provide a reference for other metal to manufacture high-performance hybrid composites.