Spherical pore replicated microcellular aluminium: Processing and influence on properties

A method is presented that extends the replication process for the manufacture of open-celled metallic foams to include foams with spherical cells. Such foams are produced to a wide range of relative densities, tested for mechanical behaviour and resistance to fluid flow in the Darcian regime, and characterized using synchrotron X-ray microtomography for their internal architecture. It is shown that the effect of cell shape on uniaxial mechanical properties is negligible if the cells are roughly equiaxed. Spherical and angular pore foam mechanical properties differ, however, if the angular particles are more irregular and their aspect ratio deviates from unity; current micromechanical models assimilating pores to spheroids do not account for this difference. The permeability is, on the other hand, relatively insensitive to details of pore shape, matching well predictions of a simple spherical pore model in all cases.