Effect of Zinc Content on the Mechanical Properties of Closed-Cell Aluminum Foams

The closed-cell aluminum alloy foams were fabricated by the molten body transitional foaming process. In this research, the closed-cell aluminum foams were successfully fabricated with different zinc contents (4, 8, and 12wt%) using the melt-foaming method and blowing agents. Calcium was used to increase the melt viscosity and CaCO3 was used as a foaming agent. Uniaxial compressions tests were performed on the foams to investigate the effects of zinc addition on the mechanical behavior of fabricated Al–Zn foams. The effects of zinc additions on the foam properties such as density, porosity, pore diameter, yield strength, plateau stress, and energy absorption were investigated. According to the X-ray analysis results, the reaction between Al–Ca–Zn leads to the formation of oxide phases in the melt and increases the melt viscosity and also the cell wall thickness. Foam with 4wt% Zn has a good yield strength and longer plateau region than pure aluminum foam due to the uniform cell structure. The foam density and the absorbed energy per unit volume of Al–Zn foams increase with increasing zinc content to foams.