Interfacial shear strength enhancement of a 30 wt% CF/PPS-A2024 joint via Al2O3-enhanced chemical reactivity and mechanical interlocking mechanisms

To improve the low bonding strength at the inert polymer-metal interface, this study applies ultrasonic-aided corrosion and silane coating processes to the surface treatment of aluminum alloy 2024 (A2024). Meanwhile, 30 wt.% carbon fiber reinforced polyphenylene sulfide (30 wt.% CF/PPS) was modified using Al 2 O 3 particles to enhance its mechanical strength and chemical inertness. As a result, the tensile strength, flexural strength, and impact strength of PPS were improved from 117.1 MPa, 179.7 MPa, and 5.85 KJ/m 2 to 125.6 MPa, 187.9 MPa, and 6.32 KJ/m 2 , respectively. Following thermal treatment of the injected samples, the silane molecules successfully formed covalent bonds with Al 2 O 3 on both sides of the 30 wt.% CF/PPS-A2024 joint the interface, significantly enhancing the interfacial adhesion. Benefiting from the synergistic effects of mechanical interlocking and chemical bonding at the interface, the tensile shear strength of the 30 wt.% CF/PPS-A2024 interface reached 60.6 MPa, representing a 117.4% increase compared to the untreated interface.