Processing and Characterization of Open–Cell Aluminum Foams Obtained through Infiltration Processes

This work reports the fabricating of open–cell Al foams which were manufactured through infiltration processes employing a device with controlled atmosphere for the fusion and infiltration processes of the metal, which is separate from the heating furnace. The device allows controlling its internal atmosphere with an inert gas to protect the metal of the fast oxidation, avoiding the employment of a controlled atmosphere furnace (a furnace of this kind incorporate the heating and the control atmosphere systems itself). The metal used for the present study was Al in ingot form with 99.8% purity. Equiaxial NaCl granules in three ranges of particle sizes were chosen as space holder particles (SHP). The range I from 4.7 to 4.0 mm, the range II from 4.0 to 3.3 mm, and the range III from 3.3 to 2.0 mm. The obtained foams showed a highly porous structure with interconnected cells in all cases. The maximum porosity and minimum density values resulted to be ∼73.7% and ∼0.71 g/cm3, respectively. This work demonstrates that it is possible to use NaCl with different particle sizes in the manufacturing of Al foams with high porosity, low density and roughly 100% interconnected cells employing a device with controlled atmosphere and an electrical furnace, both separated from one another. The results are interpreted in terms of NaCl particle sizes and its content in the samples.