基于Ag纳米线的微纳电解加工研究

摘要

The scanning tunnel microscope probe,which tip is self-assembled of Ag nanowire,is used as a tool electrode in micro-nano electrochemical machining. It is found that the Ag nanowires occur reaction with electrolyte and dissolve in the machining process. In order to improve the stability of Ag nanowire in micro-nano electrochemical machining, the method of sputtering Au on the surface of Ag nanowire is developed. The research indicates that the nanowire electrode dissolves yet during electrochemical machining when the thickness of the sputtering layer is about 27 nm and 55 nm due to loose sputtering layer,while it is bent because of large internal stress when the thickness of the sputtering layer is about 310 nm and the bent nanowire falls away from the tip of scanning tunnel microscope probe due to decreased adhesion at the juncture. The Ag nanowire is still unchanged in the electrochemical reaction,when the thickness of the sputtering layer is about 150 nm and 240 nm. The nanowire electrode with the thickness of the sputtering layer of about 150 nm is used in micro-nano electrochemical machining. The groove of 110 nm in depth and 1 μm in the entrances width is prepared successfully by using the pulse period of 50 ns,pulse on-time of 6 ns,the voltage of 4 V and 0.1 mol/L H2SO4 electrolyte in the surface of high-temperature alloys workpiece.%采用尖端自组装了Ag纳米线的扫描隧道显微镜探针作为微纳工具电极进行电解加工试验研究。加工过程中发现Ag纳米线与电解液发生反应而溶解。为了使Ag纳米线稳定用于电解加工，对其表面溅射金属Au。试验结果表明，当溅射层厚度为27 nm和55 nm时，溅射层不够致密，Ag纳米线仍会发生溶解；当溅射层厚度为310 nm时，过厚的溅射层使Ag纳米线发生弯曲，从而使Ag纳米线与扫描隧道显微镜探针尖端的结合力变小并发生脱落；当溅射层厚度为150 nm和240 nm时，Ag纳米线在电解加工中均能保持稳定。采用溅射层厚度为150 nm的Ag纳米线进行微纳电解加工。在0.1 mol/L的H2SO4电解液中，施加电压4 V、周期50 ns、脉宽6 ns的纳秒脉宽脉冲电流，在高温合金试件表面成功加工出微纳沟槽，沟槽深约110 nm，入口最宽处约1μm。