Fabrication of aluminum foam with complex shapes using pin screen mold and effect of arrangement of pins on its surface morphology

In this study, a pin screen mold was proposed for fabricating Al foam with complex shapes. A pin screen mold can easily form a complex surface simply by moving the pins upward and downward. First, the effect of the interval between the pins and the downward force against the heads of the pins on the surface morphology of the obtained Al foam was investigated. Little protrusion of the Al foam through the gaps between the pins was observed for the minimum interval between the pins even though a downward force was applied. The extent of protrusion increased as the interval between the pins increased, and this tendency became more apparent as the downward force increased. There is a limit to the interval between the pins for which the shape of the Al foam is retained without collapse. The porosities of the obtained Al foam were between 75 and 84% and the pores were homogeneously distributed in the obtained Al foam. Moreover, the star-shaped Al foam with homogeneously distributed pores was fabricated by preparing a pin screen mold with a star-shaped cavity. In addition, the Al foam with a star-shaped outline and homogeneously distributed pores was fabricated by preparing a star-shaped gap in the pin screen mold.