Fabrication and Three‐Point Bending Behavior of Aluminum Foam Sandwich via Controlled Atmosphere Brazing

Herein, aluminum foam sandwiches (AFS) with metallurgical bonding interfaces are fabricated by controlled atmosphere brazing. The interfacial characterization is observed by scanning electron microscopy, and effect of core densities (0.37, 0.49, and 0.58 g cm⁻³) on mechanical properties is analyzed. Sound brazed joints are observed, with no clear boundaries between the components. The brazing filler metal partially wraps around the cell walls of the aluminum foam core, thereby increasing the contact area between cell walls and face‐sheets, and making the transition relatively smooth. Micro‐CT is used to investigate the deformation mechanism of AFS during quasistatic three‐point bending tests. The initial failure mode of all AFS panels is asymmetric core shear failure on one side of the AFS, with no interface debonding. The flexural load–displacement curves of three‐point bending tests exhibit four stages: 1) nearly linear elastic deformation stage; 2) initial failure stage; 3) plateau stage; and 4) failure stage. The specific flexural strength and specific energy absorption of AFS are found to increase with the core density.