HEIDENHAIN TNC 406 - Manual (Page 80)

HEIDENHAIN TNC 406, TNC 416 59
4.5 F
u
ndamentals of Spar
k Er
osion
After a certain length of time (the ignition delay time), a discharge
channel suddenly forms across the bridge of particles, and current
starts to flow between the electrode and the workpiece. The current
flow increases the temperature in the discharge channel, and further
electrically charged particles are created (ions). The current increases.
The temperature in the discharge channel becomes so great that the
dielectric fluid there vaporizes.
The discharge channel expands in the middle while at the electrode
and workpiece it becomes narrower.
The temperature increases to a point where the surfaces of the
electrode and workpiece melt. Part of the molten metal vaporizes.
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