Engineering compression constitutive model of closed-cell aluminum foams at high and low temperatures

Abstract

Due to excellent properties, such as lightweight, high specific strength, energy absorption ability, vibration reduction, sound insulation, heat insulation, and electromagnetic wave shielding, closed-cell aluminum foams have broad potential applications in diverse energy absorption fields. However, the comprehensive mechanical performance customization presents significant challenges due to the complexity of service environment temperatures and internal microstructures. Therefore, the X-ray computed tomography (CT) technology with a maximum resolution of up to 0.5 μm was used for three-dimensional (3D) geometric reconstruction and structural feature analysis of aluminum foams, such as porosity, pore diameter, and pore wall thickness, micropore. Then, quasi-static compression tests were conducted under high-temperature conditions (up to 600°C) and low-temperature conditions (down to -100°C) to study the deformation mode and energy absorption capacity. The results indicate that the position of the collapse deformation tends to move from the top to the bottom as the density increases. Aluminum foams exhibit a strengthening characteristic under low-temperature conditions but exhibit a softening characteristic under high-temperature conditions. The transition temperature from brittle mechanism to ductile mechanism is between 200 °C and 300°C. Finally, the engineering compression constitutive model was established, which can describe the mapping relationship between geometric structure, service temperature, and mechanical properties, providing an essential theoretical basis for the service performance evaluation of closed-cell aluminum foams in high-temperature and low-temperature environments.