Study Of The Mechanism Of Field Induced Jet Micro EDM

Electrical discharge machining (EDM), as an untouched machiningmethod, for the special advantages such as lower cost and none macroapplied force, becomes a promising method for micro machining in manyfields. By controlling the electric discharge energy per pulse, extremelysmall discharge crater can be obtained, thus, EDM is of the potential ofmicro/nano meter-scale machining capability. The tool electrode wear andits compensation however, have always been difficult problems inmicro-EDM. Nanometer scale tip of probe is usually used as tool electrodein nano-EDM and the tip of the electrode can be eroded easily and quickly.This is an important obstacle to constrain the nano-EDM to step forwardfor practical application.A novel micromachining method namely field induced jetmicro-EDM was proposed in this paper, in which the electrical fieldinduced jet is used as the micro tool electrode. The diameter of the fieldinduced jet can be smaller than several micrometers and the problem ofelectrode wear does not exist at all in the machining process. Due to thefact that the electrolyte can be supplied automatically by capillary effectand electric field, it is not necessary to use pumps or valves.Firstly, a field induced jet micro-EDM system was designed andintroduced, including the emitter, the high voltage power, the electrolyteand other accessories. The3D model of field induced jet micro-EDM setupwas build through Solidworks to ensure the good fit between differentparts of the experimental system. The principle of the field induced jetmicro-EDM was also explained.Then a high speed camera system was set up to observe the field induced jet micro discharge phenomenon. It was found that the fieldinduced jet micro discharge phenomenon was a periodic process. Itsfrequency was about140~250Hz. The field induced jet collapsed after thedischarge between the tip of the jet and the workpiece, however, it couldbe generated again in the next cycle.Lastly, a series of experiments were carried out to investigate thefeasibility of the field induced jet micro-EDM. It was found that theworkpiece material can be effectively removed with a crater size of about2μm in diameter. The preliminary experimental results show that the fieldinduced jet micro-EDM is an effective micromachining method.