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

Abstract

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/cm 3 , 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.

Melt Processing and Characterization of Al-SiC Nanocomposite, Al, and Mg Foam Materials

“…This is in full harmony with what is stated in other studies [21,28]-that the tiny strut thickness and the high level of the porosity can result in a degraded mechanical behavior. Under applied compressive or tensile stresses, the foam material starts to fail by the cracking of the thin struts that provide the weakest points for crack initiation and propagation.…”

“…The previous studies [13,21] focused on melt processing of metallic foam and reported that the melt infiltration using the NaCl particles with an average particle size smaller than 1 mm is extremely difficult. Decreasing the size of the particle space holder results in an elevated pressure opposing the infiltration due to the capillary pressure and the friction between the melt and NaCl Reproducing the same cellular morphology of different metals of Al, Mg, and Al-SiC that already display high diversity in melt characteristics (viscosity, fluidity, density, etc.)…”

Monitoring the influence of sodium chloride particle size on the physical, me-chanical properties and structure of samples of porous aluminium materials

“…By solidification of these metal melts, a heterogeneous system is formed consisting of metal and sodium chloride particles. Various technologies are used in the production of porous materials, [17], [18], [19], [20]. Other research preffered instead of sodium chloride particles of sand bound, for example, by furan resin or ceramic particles bound by gypsum.…”

Study on Preparation of Foamed Zn-Al Eutectoid Alloy by Air Pressure Infiltration Process

“…The commercially available salt (NaCl), a white crystalline, density 2.16 g.cm -3 , melting point 804 ℃, boiling point 1413 ℃, is soluble in water [5]. The commercially available salt particles are baked at lower temperatures about 150 ℃ for 12 hours, removal crystal water, avoid salt particles burst from the broken, so the gap between particles that the metal.…”