Press Forming of Aluminum Foam during Foaming of Precursor

Abstract

Al foam was press-formed utilizing a steel mesh die during the foaming of the precursor to shape the Al foam. The effects of the temperature of the precursor and the pressing velocity during press forming on the forming behavior of the obtained Al foam were investigated. It was found that Al foam was sufficiently softened above the liquidus temperature to conduct press forming. In contrast, press forming cannot be conducted below the liquidus temperature. The press forming of Al foam should be conducted after the Al foam has been sufficiently foamed above the liquidus temperature to obtain high-porosity Al foam. No extrusion of Al foam through the mesh openings occurred even when press forming was conducted above the liquidus temperature. The Al foam and steel mesh were easily separated. The mesh pattern was clearly observed on the surface of Al foams. There is little effect of conducting press forming on the pore structures of the obtained Al foams regardless of pressing velocity. Al foam with a triangular cross section having the same shape as the steel mesh die and a porosity of approximately 80% was obtained. The press-formed Al foam sufficiently filled the steel mesh die. Consequently, it was demonstrated that the press forming of Al foam after sufficient foaming is effective for fabricating Al foams with complex shapes.

Fig. 10 (a) Steel mesh die used to fabricate Al foam with a triangular cross section. (b) Vigorously foamed precursor just before the lamps were turned off. (c) Al foam after the completion of the press forming. (d) Obtained Al foam with triangular cross section with p = 78.4% and (e) its cross-sectional X-ray CT image.