Technological capabilities of the holes electrochemical machining using fixed cathode-tool

The technological possibilities of electrochemical dimensional machining of copper using fixed cathode-instrument are considered. The cathode is hollow to supply the electrolyte into the processing area. It is proposed to use the scheme with a horizontal position of the cathode, which permitted to use the electrolyte stream as the forming tool. The dependence of the needled depth change in time that indicates a decrease in processing speed with increasing electrode gap is obtained. This fact is confirmed by decrease in current density during processing, and can be explained by the increase in the ohmic resistance of electrolyte flow with the increase of the electrode gap. It is found that increasing technological voltage on the electrodes leads to the increase of treatment depth and the diameter of the inlet hole. Changing the overpressure of the jet from 0.3 to 0.8 MPa had no significant influence on processing productivity and on the regularities of the hole formation. It is shown that the increase in diameter of the cathode-tool is accompanied by a growth in both the depth of processing and the diameter of the inlet hole. The possibilities for further improvement of the electrochemical machining of a small-diameter holes to increase the productivity of the process and improve the accuracy parameters. Electrochemical machining scheme with fixed cathode-tool results in a significant loss of accuracy of the hole by cone forming. To eliminate this disadvantage it is necessary to stabilize the electrode gap using a so-called scheme of non-stationary cathode-tool. It allows us to improve the accuracy of the needling and also to increase to some extent the productivity of the process. Further improving of Electrochemical machining of holes in terms of increasing productivity requires finding ways to current density increasing by combining with other electro-physical processes.