Abstract:

In this study, holes were drilled on X153CrMoV12 cold work tool steel with high hardness (60-62HRC), which is difficult and costly to drill with conventional methods, using 3 mm brass electrodes on a fast hole drilling machine by electro-erosion. In this context, the effects of three different amperes (5, 6, 7 A), three different voltages (1, 2, 3 V), six different pulse on-time (18, 22, 24, 26, 28, 29 μs), four different pulse off-time (3, 6, 8, 10 μs) parameters on the processing time and the Kerf formed in the drilled holes were determined by macro analysis and analytical measurements. As a result of the analysis, it has been determined that the parameter with the highest effect on the kerf angle and machining time is the machining current. The processing time increased with the increase of the pulse off time on the other hand the increase in current, voltage and pulse on time decreased the machining time. In general, it has been determined that the processing parameters have a non-linear effect on the kerf due to the pressure flushing of dielectric liquid from the inside and outside of the electrode material, and the evacuation of the abraded particles from the environment. The lowest kerf angle and the highest processing time were achieved using the operating parameters of 7A maximum current, 3V voltage, 29 μs pulse on time and 3 μs pulse off time. In addition, a dimensional accuracy of 170 μm in the hole inlet diameter and 220 μm in the output diameter was obtained.

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