Preparation Technology of Aluminum Foam Sandwich Panels by Powder Metallurgy and Optimization of Cellular Structure

The metallurgical bonding of panel and core layer of aluminum foam sandwich can be realized by the powder metallurgy method, and the advantages in the preparation of near net shape aluminum foam part are prominent. The preparation process of aluminum foam sandwich by powder metallurgy method was improved, and the cellular structure was optimized in this paper. AlMg4Si8 aluminum alloy powder was selected as a core layer component, and the edge welding seal preprocessing of the steel panel was carried out. The results show that the foamable precursor with higher densification degree and metallurgy combination of panel and core layer can be obtained by hot-rolling of the coating panel filled with the core layer, when the apparent density of the core layer powder is 1.12 g/cm3, at a rolling pressure of 1500 kN, a rolling speed of 0.06 m/s and a rolling reduction rate of 55%. In addition, the H2 decomposed at the initial stage of foaming was wrapped by the liquid Sn when the blowing agent TiH2 was pretreated by coating of the low melting point Sn, so that the diffusion of H2 between the voids in the solid matrix was avoided and the generation of cracks was reduced. Finally, aluminum foam sandwich with uniform cellular structure and 72.7% porosity can be obtained by foaming of foamable precursor at 720℃ for 300 s. © 2020, Science Press. All right reserved.