The Research On The Electrochemical Micromachining(ECMM) With Nanosecond-Pulse Generator

Electrochemical machining (ECM) removes the workpiece material in the form of ion based on the anodic dissolution principle in the electrolyte, this processing has great advantages in the field of micromachining such as good surface quality, wearless tools, non-contact, independent with material hardness, etc. It has become one of the key technologies in aerospace and defense industry production. In this thesis, some key techniques of micro-electrochemical machining are studied such as the mechanism of micro- electrochemical machining, preparation of micro-tool electrode, design of nano-second pulse generator.The mechanism of micro-electrochemical machining with transient process in between the electrodes is given on the basis of electric double-layer. According to the Faraday's law and the electrochemical polarization of the Butler-Volmer equation, The equivalent circuitry of the electro- chemical micromachining is described as well.According to the research of Micro-ECM, the design of nano-second pulse generator is carried out. The device consists of pulse control circuit, optical coupling isolation, MOSFET driver, waveform control unit, pulse voltage regulator modules, those are implemented based on CPLD and MOSFET. The experiments of micro-holes machining are conducted. The effects of tool electrode, electrolyte, inter-electrode gap and pulse parameters on the processing characteristics are investigated.