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

Abstract

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 fmt place but too dependent on the compounds in the dielectric work liquid. For the projection the technological parameter like in particular roughness, are knowledge uecessary 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 Microscopy (CUM) for the determination of the craters topologies.

Influence of selected groups of additives on breakdown in EDM sinking

“…1. Measuring cell for HSFC and single pulse analysis [2]. charges in order to simulate more real gap conditions even at a single pulse discharge.…”

“…To solve these problems, a special measuring system has been developed at the IGET (Institute for Fundamental Electrical Engineering and Electromagnetic Compatibility) for the optical and electrical characterization of single pulses and sequences of ignitions [2]. The developed measuring system consists of a measuring cell, a high speed framing camera (IWF Dresden), a process energy supply (single pulse generator), a guidance and positioning system and an electrical measuring system for current and voltage.…”

Influence of liquid additives in electro-erosive micromachining (EDMM)

“…For the electrical characteristics of these single pulses a measuring system consisting of a measuring cell, a single pulse process energy source, a guidance and positioning system and an electrical measuring system for current and voltage courses was developed [1]. The electrode arrangement for creating the discharge was carried out as peak-to-plate geometry.…”

Demands on process and process energy sources for the electro-erosive and electrochemical micro machining

“…4 shows how by way of a short-time effect of the streamers a minimization of the removal-effective pulse energy might occur. This effect has already been used for the EDM in gases [8,9], yet here the cleansing of the working gap for gap distances << 5 μm is a problem, especially in case of complex structures. A solution could also be gained by way of the grouping of needle pulses (needle pulses), which steadily cause a short-time breakdown and reignition of the discharge channel.…”