Preparation and characterisation of cellular metals (MEMoRIAL-M2.6)

Due to their outstanding properties metallic cellular structures are in the focus of research and development. A great number of potential applications has yet been addressed, major interest is in such fields like biomedivcal devices, support stuctures with high tortuosity für fluiddynamic applications and support structures for active components in heat transformation applications such as adsorption heat storage and adsorption heat pumps.

However, the specific surface area of those structures is commonly too small. Moreover, cellular structures may cause mechanical instabilities of materials if critical heigths or diameters are exceeded. To bridge this gap, a novel manufacturing strategy has been developed and transferred to aluminum and to copper open cell foams. In order to increase the porosity in these foams a reticulation process for foam manufacturing was combined with two freeze processing steps. This resulted in the formation of planar pores in the struts of the metallic foams and a significant increase of the total porosity. Despite of the higher porosity, both metallic foams are mechanically stable, and, the proof of principle showed, that the amount of active components - the novel-type aluminum foams were loaded with the zeolite SAPO-34, and the highly-porous copper foam was loaded with the MOF HKUST-I - is significantly higher compared to those foams processed without additional freezing steps.