| Abstract Scope |
Nanoporous metals and alloys can now be made through a wide range of methods. One of the newest uses an environmentally friendly approach of low-temperature oxide reduction in powder metal samples. Oxide reduction provides a simple and scalable means for pore formation, but the overall surface area is modest, and accessibility to the porosity can be improved. This presentation discusses a hybrid method of oxide reduction and dealloying used to create hierarchical porosity in two stages. In the first step, oxide reduction of an alloy produces a relatively coarse nanoporous structure, and in the second step dealloying is used to produce a fine nanoporous structure in the remaining ligaments. Being that the precursor is a powder metal, the process remains scalable and creating functional devices is readily envisioned. The unique benefits and limitations of mechanical alloying, oxide reduction, and multi-stage dealloying for nanoporous metals are discussed. |