An Effective Approach to Get Aluminum Foam Sandwich with High and Stable Interfacial Properties

The interfacial mechanical characteristics of sandwich structures are crucial in defining the comprehensive mechanical performance of the whole structure. Nevertheless, in practical applications, the interface often emerges as the weakest segment due to potential defects in the interface of porous metal sandwich plates (PMSP). This study aims to explore the regulatory mechanisms influencing the mechanical characteristics of nano-SiO₂-reinforced aluminum foam sandwich structure (AFS) interfaces and to propose an effective strategy to achieve AFS interfaces with superior and stable mechanical properties. Results indicated that surface modification conditions and the amount of nano-SiO₂ introduced are the primary process variables determining the strength of the AFS interface. The modified silane coupling agent was capable of enhancing its dispersion in the epoxy resin, thereby improving the interfacial strength of AFS. The most significant enhancement in interfacial strength occurred at a nano-SiO₂ concentration of 0.4 wt %, although a marked reduction in interfacial strength was observed with further increases in the nano-SiO₂ content. The overall strength and energy absorption capacity of AFS were enhanced by 14.65% and 405.43%, respectively, through the utilization of this enhancement method. More importantly, the AFS produced using this method demonstrated a stable performance and high repeatability.