The tensile and compressive stress-strain behaviour of closed cell aluminiu
m alloy foams (trade name "Alulight") has been measured and interpreted in
terms of its microstructure. It is found that the foams are anisotropic, ma
rkedly inhomogeneous and have properties close to those expected of an open
cell foam. The unloading modulus and the tensile and compressive yield str
engths increase non-linearly with relative density. The deformation mechani
sms were analysed using image analysis software and a d.c. potential drop t
echnique. The scatter in results is attributed to imperfections within the
foam. These include non-uniform density, weak oxide interfaces, and cell fa
ces containing voids and cracks. (C) 1999 Acta Metallurgica Inc. Published
by Elsevier Science Ltd. All rights reserved.