Using Powder Metallurgy and Oxide Reduction to Produce Eco‐Friendly Bulk Nanoporous Nickel

A low cost and scalable powder‐based method for producing nanoporous Ni is demonstrated, and the only processing by‐product is water vapor. This is achieved by creating a metal–matrix composite of Ni and NiO that is then reduced under dilute hydrogen to create pure Ni with nanocrystalline structure and nanoscale porosity. The technique is demonstrated in loose powder and in thin and bulk compacts with centimeter dimensions. These compacts can withstand extensive deformation without disintegrating, performing similarly to wrought Ni in specific strength. The unique processing strategy and resulting material can be readily extended to other metals and alloys.