Cellular Metals - from Aluminium Foams to Steel Matrix Syntactic Foams
The presentation provides an overview of activities at Fraunhofer IFAM and University of Bremen related to the field of cellular metals. The range of materials covered extends from aluminium and aluminium alloy foams produced according to the so-called powder compact melting or Foaminal™ process to latest developments in metal matrix syntactic foam. Issues processing as well as properties are discussed and application scenarios presented. Foaminal™ materials have been at the beginning of the renaissance of cellular metals for structural purposes. Since then, they have found their way to commercial application – nevertheless, a number of research issues remain open, such as a full understanding of foam stability. For such reasons, and in order to cut costs, further concepts like the so called APM foams have been developed, which essentially separate part shape generation from the actual metal foam expansion, thus facilitating processing as well as costs while at the same time improving the reproducibility of properties. Further developments building on the original APM technique include the development of hybrid polymer/aluminium foams as well as the use of cold-setting epoxies as matrix of the polymer foam component. Hybrid foams of this kind can in principle be perceived as a special type of syntactic foams, even though in their case the typically dense matrix is of cellular character, too. However, true syntactic foams have also been developed at Fraunhofer IFAM, both based on an infiltration (aluminium, zinc) and a powder metallurgical route (iron, Invar, different grades of steel), in the latter case following the metal powder injection moulding (MIM) route and relying either on hollow glass microspheres or alumina-silicate cenospheres as porosity-providing filler material: Their processing and constituents will be explained and the current state of knowledge as well as future research directions with respect to materials, structures and properties and their correlations discussed.
PDF available
Dr.-Ing. Dirk Lehmhus
MAPEX Center for Materials and Processes & Managing Director,
ISIS Sensorial Materials Scientific Centre, University Bremen
Wiener Straße 12
28359 Bremen
Germany
| Phone | +49 421 5665 409 |
| +49 421 5665 499 Secretary | |
| Dr.-Ing. Dirk Lehmhus | |
| Http | Dr.-Ing. D. Lehmhus, ISIS Sensorial Materials |
| ISIS Sensorial Materials | |
| MAPEX Center for Materials and Processes |