One-Step Method for Fabricating Porous Copper with Hierarchical Porosities by Dealloying Multi-Phase Cu–Mn–Al Alloy

The bulk porous copper structures with three levels of pore size from macro- to micro- to nano-scale were prepared from Cu–Mn–Al alloy through a facile one-step dealloying process. The excellent performances, such as hierarchical porosity, ultralow density (theoretical density at 0.53 g/cm3), and stable mechanical properties, were obtained in these copper structures which could be widely applied in many potential industrial applications. In addition, the process and mechanism of the pore formation was well investigated by SEM and EDX in this paper. The experimental results showed that the hierarchical multi-scale porosities in bulk copper structures were successfully fabricated by the one-step dealloying method. The macro-pores (up to 70 μm in major axis) and the micro-pores (about 2˜5 μm in diameter) in this sample were obtained from the removed high-purity Al phase of the precursor alloy, while the nano-pores (about 70˜100 nm in diameter) were generated from the dealloyed intermetallic compounds of Al2Cu and Al11Cu5Mn3, respectively.