Three-dimensional open-cell macroporous iron, chromium and ferritic stainless steel

Open-cell macroporous Fe, Cr and their alloys were prepared by dealloying with a metallic melt. By immersing (Fe, Cr)30Ni70 precursors in a Mg melt, Ni selectively dissolved into the Mg and the remaining components formed a bicontinuous structure. Analyses of the thermal coarsening in the melt reveal that evolution of the porous structure is controlled by interfacial diffusion between the melt and precursor solid. The underlying mechanism for the nanoporous structure formation is therefore the same as that in aqueous solution.