Characterization of open celled metal foams

Abstract

Open cell metal foams are a type of engineered material can be characterized by high porosity, high strength to weight ratio, tortuous flow paths and high surface area to volume ratio. It is the structure that gives the metal foams the characteristics that make them well suited for many application including heat exchangers. In this work, the structure of open celled metal foams is quantitatively characterized using an image analysis based method in order to predict the evaporative heat transfer of the metal foam using the fluid permeability. Several image processing algorithms were developed to quantitatively characterize the porosity, surface area per unit volume and the tortousity of metal foams from digital images of the cross sections of the material, and an expression was used to calculate the fluid permeability. An algorithm was developed to partion the pore space in the digital images so that individual cells within the structure could also be quantitatively characterized. Tools were also developed to predict the structure of open celled foam processed using the sacrificial template method by digitally constructing microstructures based the particle packing of the sacrificial templating material.