Technological parameters of process of electroerosive piercing of microholes at different processing depths

In the paper, results of the research of dependence of a process productivity and wear of an electrode-tool on the depth of its penetration in the workpiece during electroerosive piercing of microholes are set out. It has been established that up to the depth equal to ten diameters, the wear of the electrode-tool increases insignificantly. Then, at depths from 15 to 17 diameters of the processed hole, there is a gradual increase of the wear ratio up to 90-100%. A sharp increase of the wear occurs at depths over 15-20 diameters of the processed hole. The process productivity during penetration of the electrode-tool reduces monotonically from 25-40 μm/s (at the beginning of the process) to 7-7,5 μs/s (at a depth of 15-17 diameters of the processed hole), which is explained by the wear increase of the electrode-tool and deterioration of conditions of erosion products evacuation from the interelectrode gap. It has been established that the greater wear and lower productivity correspond to the electrode-tool of less diameter, which is explained by the fact that electric modes of processing for all diameters were set as similar. (paper)