| Electrochemical machining (ECM) is a special process of utilizing metal electrochemistry dissolution principle to form parts, with the removal of the work piece ion by ion. It can offer several advantages including high efficiency, high surface quality and wide range machining material. There are three problems to be solved better to develop micro-ECM technology, stray corrosion of distributing electric field, control to electrochemical location and machining precision.In this paper, the analysis based on the equivalent circuit of pulse micro-ECM shows the relationship between electrode potential and charging time in the polarization process of ECM. According to the Bulter-Volmer equation and Faraday's Law, the theoretical model of current density and processing speed is established. And the theoretical analysis is accomplished to make out of the feasibility of utilizing nanosecond pulse power to achieve micro-ECM, as well as the impact of the electrolyte upon micro-ECM. Nanosecond pulse power supply are designed and made. The pulse wave from waveform generator is blown up by power amplification circuit, after negative pulse carrier waves filtrated, square wave pulse shortened to 100ns and up to 5MHz is gained. The output voltage can satisfy micro-ECM for the valid value from 0 to 10v and dutyfactor adjustment from 0.1 to 0.5.Adopting the process of electrochemical etching, symmetrical column electrode with 16μm in diameter and 500μm in length is manufactured on line, and solve the problem of back wimble. Replacing electrode with aiguille, micro helix electrode with 80μm in diameter and 3 mm in length is manufactured. Based on the WEDG principle of manufacturing micro axis, symmetrical column electrode with 52μm in diameter and 800μm in length is also made, and as a result, method of wire electrochemical machining tiny electrode is put forward.The electrochemical micro-machining experiment, with nanosecond pulse power supply, aims to research the influence of power supply parameters (peak voltage value, pulse duration and dutyfactor of machining voltage) and electrolyte (component, concentration) on machining clearance, taper of hole and quality of machining surface. Under the conditions of low voltage, narrow pulse duration, small duty ratio and low concentration passivation electrolyte, experiment shows that it can effectively diminish machining clearance, boost up the location of electrochemical reaction, enhance the machining precision, and at last realize micro machining. The experiment about hole and slot by using helix electrode and column electrode respectively indicates that the former is better than the latter obviously at machining rapidity and clearance for reasons of helix structure of helix electrode propitious to expel outcome during machining and renew electrolyte within clearance. Through prolonging machining time and choosing helix electrode, the taper of hole is improved remarkably but can't be eliminated. The round platform with 0.56 mm in diameter is developed by Syringe electrode molding, high precision in shape. Making use of electrochemical milling, the 190×190μm convex platform and the ancon with 14μm in width and 1mm in length are also developed, and micro structure machining is realized.
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