% IMPORTANT: The following is UTF-8 encoded. This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.
@PHDTHESIS{Simon:818826,
author = {Simon, Marek Sebastian},
othercontributors = {Reisgen, Uwe and Uhrlandt, Dirk},
title = {{O}n the mechanism of evaporation-determined arc-cathode
coupling in {GMA} welding},
volume = {1/2021},
school = {RWTH Aachen University},
type = {Dissertation},
address = {Düren},
publisher = {Shaker Verlag},
reportid = {RWTH-2021-04680},
series = {Aachener Berichte Fügetechnik},
pages = {1 Online-Ressource : Illustrationen, Diagramme},
year = {2021},
note = {Druckausgabe: 2021. - Auch veröffentlicht auf dem
Publikationsserver der RWTH Aachen University; Dissertation,
RWTH Aachen University, 2021},
abstract = {In gas metal arc welding (GMAW) process simulation, it is
desired to predict the energy transferred to the process as
well as the weld pool geometry. For this reason, the
coupling of the arc to the welded material is of high
interest, both at the cathode and anode. Although there
exists a substantial body of work on the coupling of the arc
to the cathode, the present models cannot be applied in the
conditions of GMAW welding, as they give unphysical results.
In particular, the current models usually result in very
high cathode surface temperatures, i.e. above boiling
temperature of the metals. After relevant experiments are
presented and discussed, it is concluded that the current
state of the art does not reflect the observations and that
therefore a new approach needs to be developed. Furthermore,
a dialectic argument is developed, namely that the coupling
of the arc to the cathode in diffuse attachment of GMAW must
be strongly determined by evaporation. The argument
concludes that the current transfer is mainly carried by
metal ions that are evaporated from the cathode surface and
ionized in the near cathode plasma, and that this current
transfer must be limited to below boiling temperature. The
core hypothesis is that this limit results from a decrease
of the ionization degree, due to cooling of the near cathode
plasma by the cold metal vapor. Based on this argument, a
mathematical model for the Evaporation-Determined
Arc-Cathode Coupling (EDACC), is introduced in detail. The
properties of the model are then analyzed by applying it to
a simplified computational fluid dynamics (CFD) weld pool
simulation and it shows that the model is in line with the
observed cathode surface temperatures below boiling.
Finally, also an outlook is given on possible applications
of this new understanding of the arc-cathode coupling, as
well as a discussion of open questions and current
limitations of the model.},
cin = {417610},
ddc = {620},
cid = {$I:(DE-82)417610_20140620$},
pnm = {SFB 1120 A04 - Simulationsunterstützte Ermittlung der
Wirkung von Schweißbadströmungen auf die präzise Bildung
der MSG-Schweißnaht (A04) (260043483) / DFG project
236616214 - SFB 1120: Bauteilpräzision durch Beherrschung
von Schmelze und Erstarrung in Produktionsprozessen
(236616214)},
pid = {G:(GEPRIS)260043483 / G:(GEPRIS)236616214},
typ = {PUB:(DE-HGF)11 / PUB:(DE-HGF)3},
doi = {10.18154/RWTH-2021-04680},
url = {https://publications.rwth-aachen.de/record/818826},
}
guest ::