摘要
多孔铜粉具有独特的孔隙结构和大比表面积,是适合于催化生长和化学负载的基元功能材料。但受限于粉末尺寸小、活性高,目前鲜有关于多孔铜粉制备工艺的研究。以球磨后的铜锌合金粉末为前驱体,采用气相去合金的方法成功制备了多孔铜粉。应用SEM、EDS、XRD、TEM等表征手段研究了去合金温度、时间、原始合金成分和球磨变形对粉末性能的影响。实验结果表明,孔隙结构变化是Zn原子去合金驱动力,Cu原子表面扩散和Cu原子体扩散三者互相竞争的结果。表面孔隙粗化过程受Cu原子表面扩散主导,而Cu原子体扩散会引起孔隙结构的收缩。球磨引入的位错通过提供快速扩散通道的方式降低了孔隙粗化过程的扩散激活能,加快了去合金过程的进行。制备的多孔粉末最大表面孔隙率为17%,平均孔隙尺寸为0.6~1.1μm。通过调整工艺参数,可以调控多孔铜粉的表面孔隙。
Porous copper powder is ideally used for catalytic growth and chemical loading owing to unique pore structure and large specific surface area.However,limted to small size and high surface activity of the powder,few studies on the preparation of porous copper powder were reported.In this paper,porous copper powder was successfully prepared by vapor phase dealloying using ball-milled Cu-Zn alloy powder as precursor.The effects of dealloying temperature,dealloying time,initial alloy composition and ball-milling deformation on the properties of dealloyed powder were investigated by SEM,EDS,XRD and TEM.Results indicate that evolution of pore structure is a product of the competition among the dealloying driving force of Zn atom,the surface diffusion velocity of Cu atom and the body diffusion velocity of Cu atom.The coarsening process of surface pores is dominated by the surface diffusion of Cu atoms,which causes the shrinkage of pore structure.The dislocation introduced by ball milling reduces the diffusion activation energy of pore coarsening process by providing a fast diffusion channel and speeds up the process of dealloying.The maximum average surface porosity of the prepared porous powder is 17%,and the average pore size is 0.6-1.1μm,which both can be controlled by adjusting process parameters.
作者
马若岚
熊定邦
范根莲
谭占秋
李志强
MA Ruolan;XIONG Dingbang;FAN Genlian;TAN Zhanqiu;LI Zhiqiang(State Key Laboratory of Metal Matrix Composites,Shanghai Jiaotong University,Shanghai 200240,China)
出处
《功能材料》
CAS
CSCD
北大核心
2022年第8期8085-8091,共7页
Journal of Functional Materials
基金
国家自然科学基金项目(52171143,52011530034,52050410332,51971206,51871149)。
关键词
多孔铜粉
气相去合金
动力学拟合
微米级
孔隙调控
porous copper powder
vapor phase dealloy
dynamic fiiting
micron scale
adjusting pore stucture
