Fabrication and characterization of nanoporous copper through chemical dealloying of cold-rolled and annealed Mn-Cu alloy

This study investigated the effects of the manufacturing process on the microstructure of nanoporous copper (NPC) produced using cold-rolled Mn-30 at.% Cu and Mn-40 at.% Cu precursor sheets. NPC was prepared by chemically dealloying these precursor sheets in a 4% HCl aqueous solution. The initial Mn-Cu alloys were homogenous solid solutions with good cold-rolling workability. After dealloying, Mn-30 at.% Cu and Mn-40 at.% Cu precursors formed nanoporous structures with ligament size of 122 +/- 5 nm and 97 +/- 4 nm, respectively. In addition, the annealing conditions of the precursors were strongly related to the formation of a bi-continuous nanoporous structure. This was attributed to the lower diffusivity of Mn atoms at 550 celcius than that at 750 celcius, which resulted in the slower rearrangement of Cu atoms during the dealloying process. Additionally, NPC sheets derived from annealed Mn-30 at.% Cu precursors at different annealing temperatures under the same dealloying condition exhibited ligament sizes of 223 +/- 9 nm and 149 +/- 4 nm. These results indicate that the change in the annealing temperature of the precursor significantly refined the nanoporous structure.

Automated summary

The study found that the annealing conditions of the Mn-Cu precursor sheets significantly influenced the final nanoporous structure of copper. Precursors annealed at lower temperatures resulted in a more refined nanoporous structure.