Density‐Graded Cellular Aluminum

Abstract Open‐cell metallic foams with controlled, continuous density gradients were created from polyurethane foam precursors using an investment casting method. This method, designed to improve mass‐efficiency in load‐bearing metallic foams and facilitate bonding of foams to dense materials in higher‐order structures, is described in detail, and demonstrated through pure aluminum foams with model relative density gradients. Methods for structural characterization, including non‐destructive local density mapping, are also illustrated.