Design Of Electrochemical Micromaching Setup And Related Experiments

In Electrochemical Machining (ECM), the mechanical performances, such as hardness and strength of material play no part on machining, thus ECM can offer several advantages including high efficiency, high surface quality and none tool wear. According to the machining mechanism, materials are removed through the transferring of ions based on anodic dissolution in ECM, so it could be used for micromachining when machining conditions are well controlled and machining parameters are selected appropriately.In this paper, a setup, which can be used for the machining the micro-part and micro-structure base on Electrochemical Micromachining is designed and manufactured. The setup has a stiff portal frame and a thick granite pedestal, which can make for the setup running steadily. The setup contains 3 liner motion systems with travel ranges of 50×50×100mm. The level feeding mechanism is a combination of macro-feeding and micro-feeding (Macro/Micro Dual-Drive, which is drive by step motor and piezoelectric ceramic), with the least displacement of 50nm and the positioning repeatability of 0.5μm. The tool-electrode is driven by high-speed motorized spindle, whose rotate speed around 0~24000r/min and rotating error is less than 3μm. The setup also has the observation device, the process can be observed in the monitor.The control system for the setup is also developed. The macro-driver is controlled by motion card, and the micro-driver is control by D/A converter. Through input the parameter to the control software, all the movements of the setup can be controlled by the computer, such as macro drive, Macro/Micro Dual-Drive and 2-axis motion, which can be used for electrochemical generating machining. During the machining, the control system can detect the voltage between the tool-electrode and the workpiece, and then judges the machining state to adaptive the gap between them.With the application of high-frequency-short-pulse power supply which pulse duration reach to 8μs, series experiments have been performed in the setup to confirm the machining conditions and control parameters which are in favor of the stability ofthe EMC, such as the electrolyte types and its supply mode, the feeding speed, the rotation speed of the tool-electrode, the voltage of the short circuit, the control parameters of the micro driver and so on. The rules of machining precision and machining efficiency have been studied. Series micro-structures machining are also carried out in the setup, such as the micro hole, micro shaft, narrow channel, words and micro solid-structure. The setup is also capable of fabricating tool-electrode on-line, the tiny tool-electrode of simple shape can be obtained easily by EMC, then used for less size and higher precision Electrochemical Machining.