The oxide film present along the interface between metal and pores in microcellular aluminium produced by replication depends on the leaching medium that is used to dissolve the NaCl preform: leaching in water produces a thick and irregular multilayered hydroxide layer, whereas leaching in a chromate conversion solution produces a smooth layer of oxide, approximate to 10 nm thick. The pore-size-dependent flow stress of replicated microcellular aluminium exhibits a marked dependence on the leaching process used to produce the foam when the pore size is below roughly 100 mu m. This dependence on the leaching medium is a result of the influence exerted by the outer surface oxide layer on dislocational glide in micron-sized metal struts making the foam. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.