The following conditions must be met when EDM can operate normally
1. A certain gap must be kept between the molybdenum wire and the machined surface of the workpiece. The width of the gap is determined by the working voltage, processing amount and other processing conditions.
2. EDM must be carried out in liquid medium with certain insulation performance, such as kerosene, saponified oil, deionized water, etc. the requirement of high insulation is to facilitate the generation of pulsed spark discharge, and the liquid medium also has the function of eliminating the electrical corrosion products in the gap and cooling the electrode. There is a certain gap between the molybdenum wire and the machined surface of the workpiece. If the gap is too large, the voltage between the electrodes cannot break through the dielectric between the electrodes, then the electric spark discharge can not be generated; if the gap is too small, it is easy to form a short-circuit connection and can not produce electric spark discharge.
3. The pulse power supply must be used, that is, the spark discharge must be impulsive and intermittent, Ti is the pulse width, to is the pulse interval, TP is the pulse period. In the pulse interval, the ionization of the gap dielectric is eliminated, so that the next pulse can break down and discharge between the two poles.
