Electrical discharge machining in Belarus

Electric discharge machining – machining consisting in changing the shape, size, roughness and surface properties of an electrically conductive workpiece under the action of electric discharges occurring between the workpiece and the electrode-tool.

Electric discharge machining is based on tearing of material particles from the surface by the pulse of an electric discharge. If the voltage (distance) between the electrodes immersed in the working fluid (dielectric) is set, then when they get closer (voltage increases), the working fluid breaks down – an electric discharge occurs, in the channel of which a plasma with a high temperature is formed.

Since the duration of electric pulses used in this method of treatment does not exceed 10-2 s, the released heat does not have time to spread into the depth of the material and even a small amount of energy is enough to heat, melt and vaporize a small amount of substance. In addition, the pressure developed by plasma particles upon impact with the electrode contributes to the ejection (erosion) of not only molten, but also simply heated substance. Since electrical breakdown, as a rule, occurs along the shortest path, first of all, the most closely located areas of the electrodes are destroyed. Thus, as one electrode of a given shape (tool) approaches another (workpiece), the surface of the latter will take the shape of the surface of the former.

The productivity of the process, the quality of the obtained surface are mainly determined by the parameters of electric pulses (their duration, frequency of repetition, energy in the pulse). Electroerosion processing method combines electric spark and electric pulse methods.