Permeability of aluminium foam

Abstract

Experimental measurements of the permeability of pure aluminum cellular foams, based on the Darcy-Forchheimer regime equation. The permeability of various castings of aluminum foams was measured applying the equation of the fluid flow through a porous medium, Darcy’s law, including the inertial effects term known as Forchheimer term. A series of compacted salt preforms were produced in order to create the aluminum foams by liquid metal infiltration. The foams were then manufactured and placed in the measurement stand, made from scratch and specially designed to measure both the flow passing through the metal foam and the pressure drop across the foam. The measurements were analysed to obtain the permeability and the friction factor of the foams, and then confronted with existing theory in literature. The permeability results obtained in this work, despite differing with the model they are compared to, are in agreement with the values measured in other studies for aluminum foams made by replication and with similar parameters. Therefore, the results of this work may be used to know the necessary pressure to be applied to a fluid to force it to flow through the aluminum foams. Moreover, the final properties of the foam depending on the characteristics of the preform they are infiltrated to will be described and explained, so that new aluminum foams may be produced with the desired properties by knowing which conditions has to satisfy the preform. The manufacturing data of this work may be used, therefore, to get a better understanding and improve the processing of the aluminum foams by the replication method.