Channel spreading during the spark discharge for selected conditions and working fluids

The paper presents the forms of the channel formation during spark erosion. The deviations from the cylindrical discharging channels leads to completely other removal craters and therefore for changed surface roughness. The different channel types are dependent on gap conditions and pulse parameters in the first place but too dependent on the compounds in the dielectric work liquid. For the projection the technological parameter like in particular roughness, are knowledge necessary via the channel spreading and channel form, for off-line process models. The used examination methods are High Speed Framing Camera (HSFC) for the optical observation and the Confocal Lasers Scanning a Microscopy (CLSM) for the determination of the craters topologies.