Behavior of a random hollow sphere metal foam

The quasistatic uniaxial compression behavior of both single hollow spheres and bulk metal foams comprised of the same hollow spheres is examined experimentally. The spheres are nominally the composition of a 405 stainless steel (Fe-12Cr), with a 2 turn outside diameter and 0.1 mm thick walls, and are sintered together to process the bulk foam. It is shown that to first order the bulk foam stress-strain behavior, Poisson effects, and densification may be understood on the basis of simple experiments performed on single spheres between parallel platens. These hollow sphere foams appear to behave similar to open-cell foams. Finite element modeling of finite compression of a single sphere lends further insight into the deformation process and the role of plastic bending and contact of cell walls during the process of densification. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.