Providing the Forming Accuracy During the Electrochemical Deep Hole Drilling of a Small Diameter by the Cathode - Tool with a Complete Electro - Isolating Coating

The problems of forming deep holes with a diameter of less than 1.0 mm by the electrochemical drilling with the use of a hollow cathode-tool having a complete electro-isolating coating are considered. The limitations in providing the hole forming accuracy connected with breaking down the flow hydrodynamics in the processing zone because of decreasing the value of the side inter-electrode gap by the isolating coating thickness are determined. The interrelation between the maximum attainable depth of the hole processing in copper and the thickness of the isolating coating is found. It is proved theoretically and confirmed experimentally that there is a loss of accuracy in the hole forming at a processing depth exceeding the maximum attainable value according to the conditions of the stable anodic dissolving process.