Fundamental investigation of dry electrical discharge machining (DEDM) by optical emission spectroscopy and its numerical interpretation
Abstract
Dry electrical discharge machining (DEDM) has been developed as an alternative manufacturing process to the traditional EDM in liquid dielectric media. The absence of the liquid dielectric allows DEDM to be performed by simpler and environmentally friendlier machines. The erosion in DEDM mainly occurs due to the bombardment of the workpiece electrode surface by charged particles produced by micro electric discharges. Thus, the understanding of the fundamental properties of the micro plasma is necessary to explain the erosion mechanisms in this process. Optical emission spectroscopy of DEDM single discharges and its numerical interpretation by emission spectra simulation are developed in the present work. The hypothesis of plasmas in local thermal equilibrium (LTE) is developed, whereas the formation of an electron beam in non-LTE plasmas is also considered and briefly introduced. The simulations show that large amount of different ionic species is produced from the anode workpiece material, and the estimated electron temperature profile is peaking at the plasma centre. Moreover, hot anode spots formed on the workpiece surface due to the plasma-material interactions seem to be considerably smaller than the total plasma diameter and the respective eroded crater. These characteristics indicate that DEDM produces discharges similar to anode dominated vacuum arcs, which present properties very different from EDM discharges in liquid dielectric. Mehr anzeigen
Persistenter Link
https://doi.org/10.3929/ethz-b-000122449Publikationsstatus
publishedExterne Links
Zeitschrift / Serie
The International Journal of Advanced Manufacturing TechnologyBand
Seiten / Artikelnummer
Verlag
SpringerThema
Dry electrical discharge machining (DEDM); Emission spectra simulation; Optical emission spectroscopy; Plasma in micro gapsOrganisationseinheit
03641 - Wegener, Konrad (emeritus) / Wegener, Konrad (emeritus)
Anmerkungen
It was possible to publish this article open access thanks to a Swiss National Licence with the publisher.