MACHINING SPEED EVALUATION AT ELECTRICAL DISCHARGE DRILLING WITH TUBULAR TOOL ELECTRODE

The electrical discharge drilling could be applied in order to obtain cavities in workpieces made of materials difficult to be machined by classical machining methods. Distinct factors exert influence on the drilling speed. An experimental research was designed and developed by considering the depth of the cavity achieved by means of a tubular tool electrode. One used a machining scheme involving the achieving of the work movement by test piece to the tubular tool electrode clamped on the machine tool table. In this way, the influence exerted by the spurious electrical discharges facilitated by the presence in the work gap of the metallic particles detached from the two electrodes can be diminished. Empirical mathematical models were determined by mathematical processing of the experimental results and using specialized software. The empirical mathematical models proved a high influence exerted on the drilling speed by the peak current intensity.