Machining of 1.2363 and 1.2343ESR steels using EDM

Abstract

Electrical discharge machining is an unconventional machining technology. It is commonly used in tool rooms to remove the material of the workpiece, which in turn gains a negative shape of the electrode—the tool. In order to monitor and model the responses in the form of eroding rate and surface quality, a two-level half-factor experiment was performed with one replication at the corner points and two replications at the central points, for a total of 80 rounds. Both graphite and copper electrodes of sizes 10 × 10 mm and 100 × 100 mm were used for eroding, and the influence of parameter settings: open voltage, pulse current, pulse on-time and pulse off-time was monitored. It was found that the shape of the electrode and pulse current has the most significant effect on the erosion rate. The parameters pulse current, pulse on-time and their mutual interaction significantly affect the surface roughness. Statistically significant factors influencing the occurrence of defects turned out to be pulse current, pulse on-time and material of workpiece, where it can be seen that the material 1.2343ESR is significantly less prone to the formation of surface defects.