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Abstract

One of the great advantages in Electrochemical Machining (ECM) is that there is practically no affected zone generated on the machined surface. Also, compared to the electro-discharge machining (EDM), there is no wear on the electrode. Nevertheless, the disadvantage of this process is the relatively poor accuracy, due to the dissolution that occur in the gap, generated by gas bubbles that increase the current density at the side gap. To prevent this drawback, it has been demonstrated that using ultra-short current pulses (100 ns and less) at high frequency (around the MHz), the result is an effective method that improve remarkably the machining accuracy [1]. In order to achieve ultra-short current pulses, the method of electrostatic induction feeding has been used that allows the generation of current pulses shorter than several tens of nano-seconds [1]. This technic is very simple and low cost but suffers from the following inconvenient: the pulse duration and the peak current depends on the size of the electrode (capacitance between the electrode and the machining piece) and on the machining conditions. The purpose of our development is to reach the same objectives in terms of simplicity and inexpensive generator but with a high flexibility. By changing peak current and duration, one can adapt very precisely the power and consequently the machining rate and the accuracy, adapting the generator to a multiple kind of applications. Moreover, for stable machining, we have identified and used an electrical signal allowing the process control.

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