Experimental study of an aluminum sandwich panel with aluminum-foam-filled square corrugated carbon-fiber/epoxy core fabricated by friction stir welding

This study investigates the enhancement of the mechanical performance of aluminum sandwich panels by integrating an aluminum-foam-filled, square-corrugated carbon-fiber/epoxy core, fabricated using the friction stir welding (FSW) technique. The aluminum foam was bonded to the top and bottom aluminum face sheets through FSW, while the carbon-fiber/epoxy core was adhesively bonded to the face sheets. The combined interlocking effect of the corrugated carbon-fiber core and the metallic foam filling was designed to improve structural strength and energy absorption. The influence of key FSW parameters—tool rotational speed, traverse speed, tool tilt angle, and tool penetration depth—was also examined. Mechanical performance was evaluated through three-point flexural and compression tests, and fracture morphology was analyzed using scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). The FSW-fabricated sandwich panels exhibited a flexural strength of 44.6 MPa, compared with 39.8 MPa for non-welded specimens. Similarly, the compressive strength reached 98.7 MPa, demonstrating the effectiveness of combining carbon-fiber reinforcement with aluminum foam filling and FSW bonding. These findings highlight the potential of this hybrid core configuration for lightweight, high-strength structural applications.