Manufacturing and characterization of open-cell aluminum foam by powder metallurgy

Metallic foams are classified into two groups based on their pore structure: closed and open pores. The variability of cell structures directly depends on the production method and the variability of parameters. Open – cell metallic foams are used as heat exchangers due to their large surface area, in filters and separators due to their properties such as high liquid/gas permeability and corrosion resistance, and in water purifiers to reduce the concentration of unwanted ions dissolved in water because they can provide liquid flow, and in silencers due to their sound absorbing feature. Due to their thermal conductivity, they are generally used in functional applications such as catalyst supports and flame arresters. In this study, open cell aluminum foams with different pore sizes were produced using the powder metallurgy method and polyurethane foam (PUF) replica technique. After the PUF model material of the foams was removed at 500 °C for 6 h, they were sintered at different temperatures such as 850, 900 and 950 °C for 6 h. Density measurement, XRD analysis, microstructure examination and compression testing were applied to the sintered open-cell foams. The highest pore ratio and compressive strength were determined in foams with a 20 ppi (porosity per inch) pore ratio sintered at 950 °C.