Preparation of Aluminum Foam Sandwich and Foam Cell

A new way to compact powder is proposed for preparation of aluminum foam sandwich, i.e., two metal plates are stacked and rolled together with Al-Si-Ca powder containing 1wt% TiH_2 foaming agent between them, which is then foamed in heating furnace. The new way not only gets rid of the disadvantage of adhesive bonding, so as to enable the metallurgical bonding to come true but also shortens the technological process and saves the energy. The morphology of the foam cell is investigated to analyze the enrichment of titanium and furrows on cell wall. The results show that rolling the powder together with steel plates can successfully form the structure of aluminum foam sandwich (AFS). The consolidation of pores and formation of the micro-pores are the main influencing factor on cell structure. The enriched titanium grains attaching to the cell wall serve a stabilization function for foam cell in foaming process, and the curved and/or furrowed cell walls are found in solidification process. So it is very important to control the solidification process.