The Mechanical Characteristics of Monolithic Nanoporous Copper and Its Composites

Nanoporous noble metals, have shown great advantages due to the high specific surface area and many advanced properties. However, the high cost is an impediment to applications. Looking for the low cost nanoporous metals and studying their mechanical properties play important roles. In this paper, the inexpensive monolithic nanoporous copper (NPC) materials are fabricated by dealloying. Microscopically, both of the bicontinuous hierarchical structures and the homogeneous porous structures at micro/nano scales are achieved. The influences of dealloying temperatures and the Cu contents in the alloy on the mechanical property of NPC are systematically studied. The engineering stress–strain curves show that the compressive yield strengths of the NPC depend on the ligament sizes with the “smaller is stronger” effect. In order to improve the yield strength of NPC, an epoxy is impregnated into the pores as the reinforced phase. The mechanical property of NPC/epoxy composites is consistent with the expected rule-of-mixture behavior in a multiphase composite material. Furthermore, the theoretical equations are given which could accurately predict the yield strengths of the pure NPC and its composites.