Fabrication of Nanoporous Copper Ribbons by Dealloying of Mn₇₀Cu₃₀ Alloy and Fractal Characterization of their Porosity

摘要

Nanoporous copper (NPC) ribbons were synthesized by free corrosion dealloying in a 6 wt.% HCl solution for different corrosion times with Mn₇₀Cu₃₀ alloy ribbons prepared by single-roller melt spinning processing equipment for precursor samples. The microstructures and components of NPC were characterized by utilizing FE-SEM and EDS analysis. Additionally, 2-value digital image technique was used to process FE-SEM images, and porous structures of copper ribbons were quantitative characterized by fractal theory. The results showed that Mn was selectively dissolved from Mn₇₀Cu₃₀ alloy ribbons in HCl solution, and prepared NPC was uniform network-like structure, with the average ligament size of 114-214 nm and the average pore size in the range of 325-520 nm for different corrosion time. Porous structure of NPC is of typical fractal characteristic with fractal dimension in the range of 1.59-1.74. Fractal dimension reflects the heterogeneity of porous structure, thus, porosity of NPC can be characterized by fractal dimension.