Interlaminar shear strength and ballistic resistance performance test of Al/CFRP laminates

This study implemented a combined surface treatment to modify the aluminum alloy substrate. Interlaminar shear strength (ILSS) tests indicated a substantial improvement in the interfacial bonding strength between the treated aluminum and the carbon fiber reinforced plastic (CFRP), which increased from 3.12 MPa to 18.72 MPa compared to untreated specimens. Scanning electron microscopy (SEM) observations revealed that initial sandpaper grinding generated numerous grooves approximately 10 μm wide on the aluminum surface, while subsequent acid-base cleaning produced micropores ranging from 1 to 5 μm in size. These surface morphologies facilitate enhanced mechanical interlocking with the resin. Furthermore, X-ray photoelectron spectroscopy (XPS) analysis verified the formation of new functional groups, specifically Al-O-Si bonds, on the treated surface, which promoted stronger chemical adhesion to the resin matrix. Leveraging this interfacial optimization, integrated Al/CFRP laminates and Al/CFRP/Al hybrid structures were fabricated using vacuum-assisted resin infusion (VARI). Ballistic tests with 1.1 g fragment simulants demonstrated that the Al/CFRP/Al laminate achieved a specific energy absorption (SEA) of 19.70 J·m 2 ·kg -1 . This work proposes a viable strategy for designing lightweight armored vehicles by integrating an aluminum alloy frame with a CFRP composite skin, effectively combining structural lightweighting with improved ballistic protection.