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Electrochemical micromachining (µECM) requires a particular pulse power supply unit (PSU) to be developed in order to achieve desired machining performance. This paper summarizes the development of a pulse PSU meeting the requirements of µECM. The pulse power supply provides tens of nanosecond pulse duration, positive and negative bias voltages, and a polarity switching functionality. It fulfils the needs for tool preparation with reversed pulsed ECM on the machine. Moreover, the PSU is equipped with an ultrafast over current protection which prevents the toolelectrode from being damaged in case of short-circuits.The developed pulse PSU was used to fabricate micro tools out of 170µm WC-Co alloy shafts via micro electrochemical turning and drill deep holes via µECM in a disk made of 18NiCr6. The electrolyte used for both processes was a mixture of sulphuric acid and NaNO3 aqueous solutions.

Electrochemical micromachining (µECM) is a nonconventional machining process based on the phenomenon of electrolysis. µECM became an attractive area of research due to the fact that this process does not create any defective layer after machining and that there is a growing demand for better surface integrity on different micro applications including microfluidics systems, stress free drilled holes in automotive and aerospace manufacturing with complex shapes etc.This work presents the design of a next generation µECM machine for the automotive, aerospace, medical and metrology sectors. It has 3 axes of motion (X,Y,Z) and a spindle allowing the tool-electrode to rotate during machining.The linear slides for each axis use air bearings with linear DC brushless motors and 2nm-resolution encoders for ultra precise motion. The control system is based on the Power PMAC motion controller from Delta Tau. The electrolyte tank is located at the rear of the machine and allows the electrolyte to be changed quickly. This machine features two process control algorithms: fuzzy logic control and adaptive feed rate.A self-developed pulse generator has been mounted and interfaced with the machine and a wire ECM grinding device has been added. The pulse generator has the possibility to reverse the pulse polarity for on-line tool fabrication.

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