采用感应熔炼与快速凝固法制备Cu含量(原子分数,下同)为33%~67%的Mg-Cu合金薄带,然后通过自腐蚀去合金化法得到纳米多孔铜材料,用X射线衍射仪(XRD)与扫描电镜(SEM)分析多孔铜的相组成和微观形貌,研究Mg-Cu合金成分与腐蚀时间对多孔铜微观结构及形貌的影响。结果表明:Mg-Cu合金中Cu含量为67%时无法形成双连续结构的多孔铜;Cu含量为33%~60%时,形成具有双连续结构的纳米多孔铜,其中Cu含量为50%时,形成均匀、细小的双连续结构纳米多孔铜,平均孔径为60~80 nm,平均系带尺寸为50~80 nm。Mg2Cu相是形成双连续结构的必要条件,而更均匀的双连续结构是由Mg2Cu相和MgCu2相协同去合金化形成的。在含有Mg2Cu相和MgCu2相的Mg-Cu合金腐蚀过程中,Mg2Cu相优先腐蚀,形成腐蚀通道,随后为Mg2Cu相和MgCu2协同腐蚀,最后是残余的MgCu2相腐蚀完全,形成双连续结构纳米多孔铜。
Nanoporous copper (NPC) could be synthesized by self corrosion dealloying with Mg-Cu alloy. Prepared by rapid quenching and induction melting the phases and microstructure of samples were analyzed by XRD and SEM. The effect of initial alloy composition on micromorphology of nanoporous Cu and the synergetic dealloying of Mg2Cu and MgCu2 was investigated. The experimental results of chemical dealloying of these Mg-Cu alloys show that nanoporous Cu with bicontinuous ligament structures can be obtained as the atom fraction of initial Cu decreases from 60% to 33% in corrosion solution, except for alloys with Cu of 67% atom fraction, which is composed of a single MgCu2 phase. For alloys with Cu of 50% atom fraction, porous structures can be obtained with more uniform bicontinuous ligament-structure nanoporous copper, with the size of nanopore from 60 to 80 nm and the size of ligaments from 50 to 80 nm. Mg2Cu is an essential condition for formation of the bicontinuous ligament structures. The synergetic dealloying of Mg2Cu and MgCu2 in the two-phase Mg-Cu alloys results in the morphologies of NPC with uniform bicontinuous ligament structure.