Fabrication of bulk graded microcellular nickel foams using combined electroless and electroplating of polymer sphere template

Graded microcellular nickel foams are a special category of nickel foams having regions with varying pore sizes. Potential applications for these functionally graded foams include heat-exchangers, energy absorption, and filtration. In this study, a new technique of fabricating bulk graded microcellular nickel foams employing a combined electroless and electro-deposition on a polymer template is presented. The polymer template is fabricated using a vacuum extraction technique. Electroless plating ensures initial nickel deposition on the polymer template and subsequent electroplating is used to control the density of the nickel deposits. The resulting foams have average porosity of around 94%.