Performance of silane-modified high-content aluminum-filled PA66 composite prepared under the function of electric field

Significant physicochemical differences between metals and thermoplastics pose challenges for achieving strong interfacial bonding under conventional forming processes. This work presents a novel approach using an external electric field (EEF) to activate functional groups at metal-polymer interfaces, forming complex chemical bonds and strong heterogeneous connections. Silane-modified PA66 composites filled with high-content aluminum spheres were fabricated. Experimental results show that the chemical bonding between Al and PA66 under EEF is due to extensive functional group reactions and secondary bonding within Al-PA66 interface, achieving a remarkable ultimate tensile strength of 65 MPa for the composite with 50 wt% Al filling. Moreover, dissimilar joints of composites and 6061T6, made by friction stir welding, exhibit high strength due to the formation of a “Novel Net-Metallurgy Bonding Structure” during frictional heat transfer. This work provides new insights and theoretical guidance for interfacial bonding in metal-polymer heterogeneous interfaces.