Processing and First Characterization of Ferrous Foams

  1. B. Jouffrey
  1. Ulrike Mohr and
  2. Wolfgang Bleck

Published Online: 9 MAY 2006

DOI: 10.1002/3527606165.ch4

Microstructural Investigation and Analysis, Volume 4

Microstructural Investigation and Analysis, Volume 4

How to Cite

Mohr, U. and Bleck, W. (2000) Processing and First Characterization of Ferrous Foams, in Microstructural Investigation and Analysis, Volume 4 (ed B. Jouffrey), Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, FRG. doi: 10.1002/3527606165.ch4

Author Information

  1. RWTH Aachen University of Technology, Department of Ferrous Metallurgy, Aachen, Germany

Publication History

  1. Published Online: 9 MAY 2006
  2. Published Print: 20 APR 2000

Book Series:

  1. EUROMAT 99

ISBN Information

Print ISBN: 9783527301218

Online ISBN: 9783527606160

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Keywords:

  • microstructural investigation;
  • metallic foams;
  • ferrous foams;
  • processing;
  • characterization

Summary

Highly porous materials on the base of high melting alloys are of increasing interest because of their structural and functional properties. A possible field of high temperature applications are advanced power plants, e.g. as cooling system in the burning chamber or as heat exchangers. Sensible materials for these purposes are stainless steel and nickel-base alloys. Open-cell ferrous foams can be produced by incorporating a mold-filling of spherical pellets on the base of sands in the liquid metal during casting. The spheres are filled in a mold form, preheated and casted with an overheated melt. After solidification the spheres are removed mechanically off the structure.

Such spheres are manufactured by pelleting casting sands. In this process the variable parameters are various types and combinations of casting sands, different grain sizes and geometries and the use of several organic binding agents. Thus, the diameters of the resulting spheres range from 2 to 8 mm and the pellets differ as well in the quality of their surface as in their green strength. The porosity of the foam is determined by the applicated spheres' diameters. Densities about 2,8 g/cm3 can be achieved.

A first characterization of the mechanical properties of the foams produced is gained through compression tests. To determine the dependence of the mechanical properties on varying porosities the tests are carried out on foams of different densities. Furthermore, a metallographic examination gives an insight into the pore structure and reveals information on pore size, pore distribution and the interconnections of the open cells.