Structural and Material Design of Open-Cell Powder Metallurgical Foams†

High porosity permeable materials have been manufactured on the basis of the highly uniform structure of foamed polyurethane since the 1950 s. This paper shows the development of open cell foams based on all kinds of steels, titanium alloys, and also open-cell molybdenum foams made by a powder metallurgical replication technique. Such materials show a wide range of physical and mechanical properties, which may be adapted to various requirements. The automotive industry, for example, needs high-temperature resistant materials with high permeability and good strength for catalytic conversion. For orthopaedic implants, the network-like metal foams made of titanium, tantalum, or steel exhibit a bone-like structure. The powder metallurgical replication route represents an economic method to process open-cell metal foams with a unique combination of properties for a wide range of applications.