Al-Cu合金成分对去合金化制备纳米多孔铜的影响

Influence of composition on dealloying of Al-Cu alloys for preparing nanoporous copper

采用快速凝固与去合金化相结合的方法制备纳米多孔铜,用XRD、SEM分析样品的相组成和微观形貌,研究前驱体Al-Cu合金成分对纳米多孔铜微观结构及Al2 Cu、AlCu协同性腐蚀的影响。结果表明:Cu原子分数为33%时,去合金化后形成具有双连续结构的纳米多孔铜;Cu原子分数为38%时,形成比表面积更高、更均匀细小的双连续结构纳米多孔铜,平均孔径尺寸约100～150 nm,平均系带尺寸约50～80 nm;Cu原子分数为43%时,形成了双连续结构的纳米多孔铜并在其中分散着纳米颗粒聚集体;Cu原子分数为50%时,形成了纳米颗粒聚集的纳米多孔铜。实验发现,Al2 Cu、AlCu腐蚀的协同作用对双连续结构的形貌有重要的影响。

Nanoporous copper （NPC） can be synthesized by free corrosion dealloying with rapidly quenched A1-Cu alloy. The phases and microstructure of the samples were analyzed by XRD and SEM. The effect of initial alloy composition on microstructure of nanoporous Cu and the synergetic dealloying of A12Cu and A1Cu was investigated. The results indicate that for alloys with Cu of 33% atom fraction, bicontinuous ligament structure can be obtained after dealloying. Bicontinuous ligament structure with higher specific surface area is obtained for the A1-Cu pre-alloy with Cu atom fraction of 38% , and the pores are uniform and fine with the size of ligament between pores from 50 to 80 nm and the nanopore size from 100 to 150 nm. For the alloy with Cu atom fraction of 43% , the NPC is composed of bicontinuous ligament structure and some nanoparticles. For the alloy with Cu atom fraction of 50% , porous structure is observed with large nanoparticles. The synergetic dealloying of A12 Cu and A1Cu in the two-phase Al-Cu alloys results in the morphology of NPC with bicontinuous ligament structure.