Fabrication and characterization of nanoporous gold composites through chemical dealloying of two phase Al–Au alloys
Fabrication and characterization of nanoporous gold composites through chemical dealloying of two phase Al–Au alloys
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DOI：
10.1039/b904052h
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发表时间：
2009-08
影响因子：
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通讯作者：
Zhonghua Zhang;Y. Wang;Zhen Qi;C. Somsen;Xiaoguang Wang;Changchun Zhao
中科院分区：
文献类型：
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作者：
Zhonghua Zhang;Y. Wang;Zhen Qi;C. Somsen;Xiaoguang Wang;Changchun Zhao
我们提出了一种在自由腐蚀条件下，通过化学脱合金化含有Al2Au和AlAu金属间化合物的两相Al-Au合金来制备纳米孔金复合材料（NPGCs）的简便方法。利用x射线衍射、x射线能谱扫描电镜和透射电镜对NPGCs的微观结构进行了表征。Al2Au和AlAu分别进行合金化，并形成NPGCs。NPGCs的微观结构由细胞内区和细胞间区组成，并表现出两种不同长度的韧带/通道的纳米孔结构。Al2Au的合金化使细胞内区域形成纳米孔结构，AlAu的合金化使细胞间区域形成纳米孔结构。此外，随着初始Al-Au合金中Au含量的增加，NPGCs中胞间区比例增加。此外，NPGCs中韧带/通道的长度尺度可以通过简单地改变合金溶液来调节。在不同的退火温度下，NPGCs表现出异常的粗化行为。与结构均匀的纳米孔金（NPG）相比，NPG具有更高的杨氏模量和屈服强度。我们可以通过改变起始Al-Au合金的组成、改变脱合金溶液以及适当的后处理，包括高温退火和室温酸处理，来定制这些NPGCs的组织、性能和应用。
We present a facile route to fabricate nanoporous gold composites (NPGCs) through chemical dealloying of two phase Al–Au alloys comprising Al2Au and AlAu intermetallic compounds under free corrosion conditions. The microstructures of the NPGCs were characterized using X-ray diffraction, scanning electron microscopy with energy dispersive X-ray analysis, and transmission electron microscopy. The dealloying of Al2Au and AlAu separately proceeds, and results in the formation of the NPGCs. The microstructures of the NPGCs are composed of intracellular and intercellular areas which exhibit two kinds of nanoporous structures with different length scales of ligaments/channels. The nanoporous structure of the intracellular areas forms due to the dealloying of Al2Au and that of the intercellular area forms owing to the dealloying of AlAu. Moreover, the proportion of the intercellular areas in the NPGCs increases with increasing Au content in the starting Al–Au alloys. In addition, the length scale of ligaments/channels in the NPGCs can be adjusted by simply changing the dealloying solution. The NPGCs show abnormal coarsening behaviors when subjected to annealing at different temperatures. In comparison to nanoporous gold (NPG) with a homogeneous structure, the NPGCs exhibit higher Young's modulus and yield strength. We can tailor the microstructures, properties and applications of these NPGCs through changing the composition of the starting Al–Au alloys, changing the dealloying solution, and adopting proper post treatment including annealing at high temperatures and acid treatment at room temperature.