Mechanical and Electromagnetic Interference Shielding Properties of Structurally Reinforced Aluminum Foam

The rapid development of wireless communication technologies has intensified the demand for electromagnetic interference (EMI) shielding materials that simultaneously deliver high shielding effectiveness, robust mechanical performance, and low density. Here, guided by heterointerface engineering and structural reinforcement, fabricates bi‐continuous interpenetrating porous composite structures (BIPCs) by integrating ZL111 alloy lattice struts with an aluminum foam (AF). Three reinforcement architectures are designed: a cubic‐symmetric framework with unidirectional struts (Structure A), a lateral reinforcement (Structure B), and a longitudinal reinforcement (Structure C). Compared with AF, all BIPCs exhibit pronounced improvements in both compressive properties and EMI shielding. Among them, Structure C shows the largest mechanical enhancement, with compressive strength, specific strength, plateau stress, and elastic modulus increased to 2.06, 1.62, 1.42, and 2.25 times those of AF, respectively, while the total shielding effectiveness (SET) increases by 6.6%. The enhanced mechanical response is attributed to the cooperative load transfer provided by the alloy struts and metallurgical bonding in heterointerfaces. Meanwhile, EMI shielding was collaboratively enhanced by reflection loss improvement from the higher electrical conductivity and polarization losses evoked by lattice distortions. This work can not only provide idea for solving the problem of synergistic enhancement of mechanical and EMI shielding properties of AF, but also give a reference for subsequent research to enhance the EMI shielding properties of BIPCs.