Influence of phase constituent and proportion in initial Al–Cu alloys on formation of monolithic nanoporous copper through chemical dealloying in an alkaline solution

An alkaline medium has been used to fabricate monolithic nanoporous copper (NPC) ribbons through chemical dealloying of melt-spun Al–Cu alloys with 33–50 at.% Cu. The results show that phase constituent and proportion in the initial alloys have a key influence on the formation of NPC. The alloy ribbons comprising one or a combination of Al2Cu and AlCu can be fully dealloyed in alkali solution only when there is no or a minor AlCu in the initial alloys. Additionally, the length scales of ligaments/pores in NPC can be broadly modulated by simply changing the amount of AlCu in the initial alloys.

Research highlights
► An alkaline medium can be used to fabricate NPC by dealloying of multi-phase Al–Cu alloys.
► The alloys with no/a minor AlCu can be fully dealloyed, resulting in the formation of uniform NPC.
► The alloy with the amount of Al2Cu comparable to that of AlCu can be partially dealloyed, forming NPC/AlCu composites.
► The dealloying of the alloy comprising almost single AlCu just can be proceeded on the surfaces.
► The length scales of ligaments/pores in NPC can be modulated in a broad size range.