Lei Jianguo, Jiang Kai, Wu Xiaoyu, Zhao Hang, Xu Bin
Guangdong Provincial Key Laboratory of Micro/Nano Optomechatronics Engineering, Shenzhen University, Shenzhen 518060, China.
Micromachines (Basel). 2020 Sep 19;11(9):868. doi: 10.3390/mi11090868.
Three-dimensional (3D) microelectrodes used for processing 3D microstructures in micro-electrical discharge machining (micro-EDM) can be readily prepared by laminated object manufacturing (LOM). However, the microelectrode surface always appears with steps due to the theoretical error of LOM, significantly reducing the surface quality of 3D microstructures machined by micro-EDM with the microelectrode. To address the problem above, this paper proposes a filling method to fabricate a composite 3D microelectrode and applies it in micro-EDM for processing 3D microstructures without steps. The effect of bonding temperature and Sn film thickness on the steps is investigated in detail. Meanwhile, the distribution of Cu and Sn elements in the matrix and the steps is analyzed by the energy dispersive X-ray spectrometer. Experimental results show that when the Sn layer thickness on the interface is 8 μm, 15 h after heat preservation under 950 °C, the composite 3D microelectrodes without the steps on the surface were successfully fabricated, while Sn and Cu elements were evenly distributed in the microelectrodes. Finally, the composite 3D microelectrodes were applied in micro-EDM. Furthermore, 3D microstructures without steps on the surface were obtained. This study verifies the feasibility of machining 3D microstructures without steps by micro-EDM with a composite 3D microelectrode fabricated via the proposed method.
用于微电火花加工（micro-EDM）中加工三维微结构的三维（3D）微电极可通过分层实体制造（LOM）轻松制备。然而，由于LOM的理论误差，微电极表面总会出现台阶，这显著降低了使用该微电极通过micro-EDM加工的三维微结构的表面质量。为了解决上述问题，本文提出一种填充方法来制造复合三维微电极，并将其应用于micro-EDM中以加工无台阶的三维微结构。详细研究了键合温度和锡膜厚度对台阶的影响。同时，通过能量色散X射线光谱仪分析了基体和台阶中铜和锡元素的分布。实验结果表明，当界面处锡层厚度为8μm时，在950℃保温15h后，成功制备出表面无台阶的复合三维微电极，且锡和铜元素在微电极中均匀分布。最后，将复合三维微电极应用于micro-EDM中，进而获得了表面无台阶的三维微结构。本研究验证了通过所提方法制造的复合三维微电极利用micro-EDM加工无台阶三维微结构的可行性。
