What's the Difference Between Holes-Porous Foam Aluminum and Closed-Porous Foam Aluminum?

Metallic aluminum foam materials come in two types based on the pore structure: open-cell and closed-cell, as shown in the figure. Open-cell aluminum foam features interconnected pores connected by pore edges, allowing for good ventilation and thus exhibiting high thermal conductivity, sound absorption, and filtration and separation capabilities. Closed-cell aluminum foam has pores that are not interconnected, with walls, and the pores are approximately spherical in shape, with a high porosity and large specific surface area. These structural characteristics determine that closed-cell aluminum foam possesses excellent mechanical properties, energy absorption capabilities, sound absorption, noise insulation, and electromagnetic shielding properties.

Foam aluminum boasts distinct features such as its light weight, low density, and variable density with changes in porosity, which is only 0.1-0.6 times the density of solid aluminum, yet it is over four times stronger than foam plastic. It also exhibits high specific strength, excellent sound absorption and insulation, electromagnetic shielding properties, and good energy absorption and vibration reduction capabilities. It is non-flammable, resistant to oxidation, and has low aging tendencies, as well as good weather resistance and strong recyclability. Consequently, it is widely used in various fields, such as for structural components in aerospace industries for thermal and heat exchange, landing gear and wing metal shell supports for spacecraft; aboard ships for vibration and noise reduction in engine rooms, control rooms, crew compartments, and equipment rooms, particularly for submarine noise reduction to prevent noise from radiating outward and achieving counter-intelligence purposes; as a building material, for large-span, steel frame structures like sports venues, aircraft hangars, and exhibition halls, where it can be used as roof material and in elevator cabins to reduce energy consumption; in the automotive industry, as lightweight, energy-absorbing, and sound-absorbing structures. Additionally, in electrochemistry, foam aluminum can serve as a carrier for active materials in lead-acid batteries, replacing traditional electrodes. As a multifunctional material with excellent properties, foam aluminum holds great development prospects across various industrial production sectors.