Plasma of electric arc between electrodes from composite materials
The investigations of the processes of the mass transfer in a discharge gap of electric arc and peculiarity of interactions of composite electrode surface with discharge plasma were carried out. The optical spectroscopy and metallographic techniques were used. The unique secondary structure of elect...
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Babich, I.L. Boretskij, V.F. Minakova, R.V. Veklich, A.N. 2017-01-06T11:30:45Z 2017-01-06T11:30:45Z 2008 Plasma of electric arc between electrodes from composite materials / I.L. Babich, V.F. Boretskij, R.V. Minakova, A.N. Veklich // Вопросы атомной науки и техники. — 2008. — № 6. — С. 159-161. — Бібліогр.: 4 назв. — англ. 1562-6016 PACS: 52.25.Os, 52.70.-m, 52.80.Mg https://nasplib.isofts.kiev.ua/handle/123456789/110763 The investigations of the processes of the mass transfer in a discharge gap of electric arc and peculiarity of interactions of composite electrode surface with discharge plasma were carried out. The optical spectroscopy and metallographic techniques were used. The unique secondary structure of electrode surface was formed by plasma of an electric arc discharge in air at arc current under 100 A. Металографічними методами та методами оптичної спектроскопії досліджені процеси масопереносу у розрядному проміжку електричної дуги. Вивчена особливість взаємодії поверхні композиційних електродів з розрядною плазмою. Виявлена унікальна вторинна структура поверхні електродів під впливом дугового розряду в повітрі при силі струму до 100 А. Металлографическими методами и методами оптической спектроскопии исследованы процессы массопереноса в разрядном промежутке электрической дуги. Изучена особенность взаимодействия поверхности композиционных электродов с разрядной плазмой. Обнаружена уникальная вторичная структура поверхности электродов под влиянием дугового разряда в воздухе при силе тока до 100 А. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Low temperature plasma and plasma technologies Plasma of electric arc between electrodes from composite materials Плазма електричної дуги між електродами з композиційних матеріалів Плазма электрической дуги между электродами из композиционных материалов Article published earlier |
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Plasma of electric arc between electrodes from composite materials |
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Plasma of electric arc between electrodes from composite materials Babich, I.L. Boretskij, V.F. Minakova, R.V. Veklich, A.N. Low temperature plasma and plasma technologies |
| title_short |
Plasma of electric arc between electrodes from composite materials |
| title_full |
Plasma of electric arc between electrodes from composite materials |
| title_fullStr |
Plasma of electric arc between electrodes from composite materials |
| title_full_unstemmed |
Plasma of electric arc between electrodes from composite materials |
| title_sort |
plasma of electric arc between electrodes from composite materials |
| author |
Babich, I.L. Boretskij, V.F. Minakova, R.V. Veklich, A.N. |
| author_facet |
Babich, I.L. Boretskij, V.F. Minakova, R.V. Veklich, A.N. |
| topic |
Low temperature plasma and plasma technologies |
| topic_facet |
Low temperature plasma and plasma technologies |
| publishDate |
2008 |
| language |
English |
| container_title |
Вопросы атомной науки и техники |
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| format |
Article |
| title_alt |
Плазма електричної дуги між електродами з композиційних матеріалів Плазма электрической дуги между электродами из композиционных материалов |
| description |
The investigations of the processes of the mass transfer in a discharge gap of electric arc and peculiarity of interactions of composite electrode surface with discharge plasma were carried out. The optical spectroscopy and metallographic techniques were used. The unique secondary structure of electrode surface was formed by plasma of an electric arc discharge in air at arc current under 100 A.
Металографічними методами та методами оптичної спектроскопії досліджені процеси масопереносу у розрядному проміжку електричної дуги. Вивчена особливість взаємодії поверхні композиційних електродів з розрядною плазмою. Виявлена унікальна вторинна структура поверхні електродів під впливом дугового розряду в повітрі при силі струму до 100 А.
Металлографическими методами и методами оптической спектроскопии исследованы процессы массопереноса в разрядном промежутке электрической дуги. Изучена особенность взаимодействия поверхности композиционных электродов с разрядной плазмой. Обнаружена уникальная вторичная структура поверхности электродов под влиянием дугового разряда в воздухе при силе тока до 100 А.
|
| issn |
1562-6016 |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/110763 |
| citation_txt |
Plasma of electric arc between electrodes from composite materials / I.L. Babich, V.F. Boretskij, R.V. Minakova, A.N. Veklich // Вопросы атомной науки и техники. — 2008. — № 6. — С. 159-161. — Бібліогр.: 4 назв. — англ. |
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| first_indexed |
2025-11-26T06:21:03Z |
| last_indexed |
2025-11-26T06:21:03Z |
| _version_ |
1850612366404747264 |
| fulltext |
LOW TEMPERATURE PLASMA AND PLASMA TECHNOLOGIES
PLASMA OF ELECTRIC ARC BETWEEN ELECTRODES
FROM COMPOSITE MATERIALS
I.L. Babich1, V.F. Boretskij1, R.V.Minakova2, A.N.Veklich1
1 Taras Shevchenko Kyiv National University, Kyiv, Ukraine, e-mail: van@univ.kiev.ua;
2 Institute of Materials Technology Problems NAS of Ukraine, lab.29
The investigations of the processes of the mass transfer in a discharge gap of electric arc and peculiarity of
interactions of composite electrode surface with discharge plasma were carried out. The optical spectroscopy and
metallographic techniques were used. The unique secondary structure of electrode surface was formed by plasma of an
electric arc discharge in air at arc current under 100 A.
PACS: 52.25.Os, 52.70.-m, 52.80.Mg
1. INTRODUCTION
The component optimization of electrodes remains in
electric industry still an important problem in developing of
composite materials with predetermined properties. It was
found in our previous investigations [1] that the plasma
temperature strongly depends on the electrode composition
and the state of its surface as well. Therefore it is necessary
to investigate the correlation of plasma parameters and
electrode surface state or its erosion properties.
The main aim of this paper is the detailed study of the
efficiency of the mass transfer processes in a discharge gap of
electric arc and peculiarity of interactions of electrode surface
with discharge plasma.
Namely, we studied the influence of plasma of a free
burning in air electric arc on the surface state of composite
materials on the copper base: Cu-Mo or Cu-W.
These materials are obtained by the copper infiltration
of the high-melting component. The last one is a porous
framework which is prepared from Mo-Co or W-Co
powder with additions of copper powder. Cobalt (up to
~2%) is added to decrease the angle of contact of copper
liquid and molybdenum or tungsten. Furthermore because
of peculiarities of the process technology the iron is
always present in such composite materials as an addition.
The matter is that a grinding and a mixing of powders is
carried out in steel ball mills. So, composite materials
Cu-Mo-Co-Fe or Cu-W-Co-Fe in fact were used.
2. EXPERIMENT
The arc was ignited in air between the end surfaces of the
non-cooled electrodes. The diameter of the rod electrodes
was 6 mm, the discharge gap was 2…8mm, and the arc
current was 3.5 and 30 A. To avoid the metal droplet appea-
ring a pulsing high current mode was used: the current pulse
up to 100 A was put on the "duty" weak-current (3.5A)
discharge. The pulse duration ranged up to 30 ms.
The structural changes in the working layer of electrodes
were investigated by the optical microscope "Neophot-2"
and the scanning electron microscope (SEM) with the X-ray
microanalyzer "JSM Super Probe-733", JEOL.
The spatial distribution of metal vapours in a dischar-
ge gap we measured by techniques of optical emission
spectroscopy (OES) [2] and laser absorption spectroscopy
(LAS) [3] as well. So, the efficiency of mass transfer in
an electric arc can be evaluated in such manner.
3. RESULTS AND DISCUSSIONS
3.1. MASS TRANSFER IN A DISCHARGE GAP
Two independent spectroscopy techniques in a study of
the spatial distribution of metal vapours were used. In OES
the temperature profiles T(r) in electric arc between
composite electrodes were obtained from relative
intensities of spectral lines CuI 521.8 and 510.5 nm. The
radial profiles of electron densities Ne(r) are obtained from
width of spectral line CuI 515.3 nm in a case of prevail
quadratic Stark broadening. The ratio of atom
concentrations Cu and Mo or W in plasma was calculated
from radial profiles of intensities of spectral lines CuI 521.8
and MoI 603.1 nm [2] or WI 589.1 [4] nm in the assump-
tion of the equilibrium of the energy level population.
The obtained electron density and the temperature in
plasma as initial parameters were used in the calculation
of the plasma composition in LTE assumption. As an
additional experimentally obtained parameter we used the
ratio of atom concentrations Cu and Mo [2] or W [4].
So, it can be possible to calculate the concentration of
any considered plasma particle in a discharge gap and the
content of any kind of metal vapours as well.
One another technique of copper vapours visualization
is LAS.
The absorption coefficient at the centre of the spectral
line 510.5 nm in arc plasma volume was measured. We
used the copper vapour laser at this wavelength. The image
of the discharge gap in a parallel laser beam was recorded
sequentially on the CCD matrix with arc and without it.
From the measured coefficient of absorption at the
centre of the spectral line κ0 we can calculate the
population of the lower level of this line Nm~κ0δλ. So, in
such manner we could realize the copper vapours
visualization in a discharge gap.
In Fig.1 (a-c) the spatial distributions of κ0 in arc dis-
charge between Cu-Mo (a) and Cu-W (b, c) electrodes are
shown. We found that the spatial and time profile of κ0 as
well as copper vapors in arc between Cu-Mo electrodes,
more or less, is stable. In contrast to this case such profile
in discharge gap between Cu-W electrodes is unstable. In
Fig.1 (b-c) two samples copper profiles are shown.
To clarify the proper cause of this phenomenon we in-
vestigated the behavior of arc discharge between two dif-
ferent kinds of electrodes. In Fig.2 (a-c) the images of arc
discharges between Cu-Mo (a) and Cu-W (b, c) electrodes
are shown.
As one can see the drop mass transfer of metal (Fig.2, c)
as well as a gas (vapour) phase transfer (Fig.2, b) is realized
in discharge gap between Cu-W electrodes. The dominated
gas (vapour) phase mass transfer of metal (Fig.2, a) is
realized in discharge gap between Cu-Mo electrodes.
PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY. 2008. № 6. 159
Series: Plasma Physics (14), p. 159-161.
mailto:van@univ.kiev.ua
0.47
1.41
2.35
3.29
4.230
2
4
6
0
1
2
3
4
κ 0
cathode
anode
l, mm r, mm
a
0.41
1.23
2.05
2.87
3.680
2
4
6
0
1
2
κ
0
cathode
anode
l, mm r, mm
b
0.36
1.08
1.80
2.52
3.240
2
4
6
0.0
0.2
0.4
κ
0
cathode
anode
l, mm r, mm
c
Fig.1. Spatial profiles of copper vapours between
composite Cu-Mo (a) and Cu-W (b, c) electrodes
a b c
Fig.2. Images of arc discharges between composite Cu-
Mo (a) and Cu-W (b, c) electrodes
In Fig.3 radial distributions of copper atom concentration
in average cross section of discharge gap between copper
(1), composite Cu-Mo (2) and Cu-W (3, 4) electrodes are
shown.
One can conclude that in Fig.1 (c) and in Fig.3 (curve
4) the results of investigation in case of drop mass transfer
of metal in the arc gap between Cu-W electrodes are
shown. Fig.1 (b) and in Fig.3 (curve 3) correspond to gas
(vapour) phase transfer in a gap between such electrodes.
0 1 2 3
1E13
1E14
r, mm
Nk 1
2
3
4
Fig.3. Radial distributions of copper atom concentration in
discharge gap between copper (1), composite Cu-Mo (2)
and Cu-W (3, 4) electrodes
To clarify the efficiency of the mass transfer processes in
a discharge gap and peculiarity of interactions of electrode
surface with arc plasma we carried out additional surface
investigations by metallographic technique.
3.2. PLASMA-SURFACE INTERACTIONS
The structural changes in a working layer of electrode
were studied by metallographic analysis of microvolumes
of a working layer.
Such secondary modified surface of electrode has a
complicated structure on the surface of the composite
electrode on a copper base under effect of plasma of a
high current arc discharge (1…100 kA) in air [1].
Another kind of unique secondary structure formation is
observed on the surface of the composite materials Cu-Mo or
Cu-W at a discharge current under 100 A (3.5 or 30 A). The
input power in this case is less than in previous one.
In Fig.4 (a) the secondary structure on the surface of
Cu-Mo electrode treated by a single pulse current of 30 A
and duration of 30 ms is shown. Surface fragments in
more detailed scales are shown in Fig.4 (b, c).
The similar formation of the secondary structure is
observed in the Cu-W composite electrodes [see Fig.5].
The directional crystallization of eutectics colonies takes
place on the above mentioned component electrodes surface
in the investigated modes of electric arc discharge. Between
these colonies the solid solution on the oxides of the compo
sition, which depends on element components in a solution
under an arc spot, is formed. Then the oxides, which have a
high saturation pressure, are vaporized. The hollow spaces
are realized in the tungstates (molybdates). These low-
melting eutectics probably form the walls of the observed
boxes on the electrodes surface (Fig.4 b, c and Fig.5, b). As
a result of the directional crystallization the unique boxes
walls are formed on the electrodes surface in the
investigated modes of electric arc operation.
160
Except particles and their conglomeration which
are formed in the liquid melt crystallization the clear facet
crystals are observed on the electrodes surface (Fig.5,a).
Such crystals can be formed in the process of condensation
from the vapour phase of erosion products which are
contained in the discharge gap.
The carried out analysis testified that the electrical
erosion of the tungsten-copper electrodes under influence
of the free burning in air electric arc occurs mainly in a
liquid phase. The formation of spheroid particles is
observed in the electrode (cathode) section confirms the
drop mass transfer in discharge gap (Fig.5, c).
4. CONCLUSIONS
The gas (vapour) phase mass transfer of metal is
realized in discharge gap between composite Cu-Mo and
Cu-W electrodes of electric arc in air. The drop mass
transfer mechanism plays significant role in a gap
between Cu-W electrodes as well.
The unique secondary structure formation is realized on
the surface of the composite materials Cu-Mo or Cu-W at a
discharge current under 100 A (3.5 or 30 A).
REFERENCES
1. A.N. Veklich, I.L. Babich, L.A. Kryachko et al. The
influence of the secondary structure of the working layer
of composition electrodes on the temperature of electric
arc plasma // Electric Contacts and Electrodes, Kiev: IPM
NANU, 2004, p.105-116 (in Russian).
2. I.L. Babich, D.V. Chukhalenko, N.I.Grechanyuk et al.
Plasma of electric arc discharge between Cu-Mo
electrodes // Problems of Atomic Science and Technology.
Series “Plasma Physics” (11). 2007, N 1, p.139-141.
3. I.L. Babich, V.F. Boretskij, A.N. Veklich. Plasma of
electric arc discharge between copper electrodes // Contr.
papers of the XVIIth Symp. on Phys. of Switching Arc
(FSO 2007) Brno 10-13 Sept. 2007 / Univ. of Techn.,
Brno. 2007, v. I, p.13 – 16.
4. I.L. Babich, A.N. Veklich, V.Ye Osidach. Investigation
of the electric arc discharge plasma between composition
electrodes on the copper base //Bull. of the Univ. of Kiev.
Series “Phys.&Math”. 2006, N.4, p.265-268.
Article received 22.09.08.
ПЛАЗМА ЭЛЕКТРИЧЕСКОЙ ДУГИ МЕЖДУ ЭЛЕКТРОДАМИ ИЗ КОМПОЗИЦИОННЫХ МАТЕРИАЛОВ
И.Л. Бабич, В.Ф. Борецкий, Р.В. Минакова, А.Н. Веклич
Металлографическими методами и методами оптической спектроскопии исследованы процессы
массопереноса в разрядном промежутке электрической дуги. Изучена особенность взаимодействия
поверхности композиционных электродов с разрядной плазмой. Обнаружена уникальная вторичная структура
поверхности электродов под влиянием дугового разряда в воздухе при силе тока до 100 А.
ПЛАЗМА ЕЛЕКТРИЧНОЇ ДУГИ МІЖ ЕЛЕКТРОДАМИ З КОМПОЗИЦІЙНИХ МАТЕРІАЛІВ
І.Л. Бабіч, В.Ф. Борецький, Р.В. Мінакова, А.М. Веклич
Металографічними методами та методами оптичної спектроскопії досліджені процеси масопереносу у
розрядному проміжку електричної дуги. Вивчена особливість взаємодії поверхні композиційних електродів з
розрядною плазмою. Виявлена унікальна вторинна структура поверхні електродів під впливом дугового
розряду в повітрі при силі струму до 100 А.
161
a b с
Fig. 4.
a b с
Fig. 5.
1. INTRODUCTION
3. Results and Discussions
3.1. Mass transfer in a discharge gap
REFERENCES
1. A.N. Veklich, I.L. Babich, L.A. Kryachko et al. The influence of the secondary structure of the working layer of composition electrodes on the temperature of electric arc plasma // Electric Contacts and Electrodes, Kiev: IPM NANU, 2004, p.105-116 (in Russian).
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