Influence of porosity on erosion behavior and hydrogen permeability of tungsten films
The erosion characteristics of dense and porous W-films deposited on Pd substrates were measured under impact of mirror Penning discharge nitrogen plasma. It is shown that the erosion rate of high porous tungsten films (up to 45% porosity) is similar to that for dense (1 – 3% porosity) tungsten f...
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Науковий фізико-технологічний центр МОН та НАН України
2006
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| Cite this: | Influence of porosity on erosion behavior and hydrogen permeability of tungsten films / G.P. Glazunov, A.A. Andreev, D.I. Baron, M.N. Bondarenko, R.A. Causey, A.M. Hassanein, A.L. Konotopskiy, I.M. Neklyudov, I.K. Tarasov, E.D. Volkov // Физическая инженерия поверхности. — 2006. — Т. 4, № 3-4. — С. 174–178. — Бібліогр.: 8 назв. — англ. |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1859808139735465984 |
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| author | Glazunov, G.P. Andreev, A.A. Baron, D.I. Bondarenko, M.N. Causey, R.A. Hassanein, A.M. Konotopskiy, A.L. Neklyudov, I.M. Tarasov, I.K. Volkov, E.D. |
| author_facet | Glazunov, G.P. Andreev, A.A. Baron, D.I. Bondarenko, M.N. Causey, R.A. Hassanein, A.M. Konotopskiy, A.L. Neklyudov, I.M. Tarasov, I.K. Volkov, E.D. |
| citation_txt | Influence of porosity on erosion behavior and hydrogen permeability of tungsten films / G.P. Glazunov, A.A. Andreev, D.I. Baron, M.N. Bondarenko, R.A. Causey, A.M. Hassanein, A.L. Konotopskiy, I.M. Neklyudov, I.K. Tarasov, E.D. Volkov // Физическая инженерия поверхности. — 2006. — Т. 4, № 3-4. — С. 174–178. — Бібліогр.: 8 назв. — англ. |
| collection | DSpace DC |
| container_title | Физическая инженерия поверхности |
| description | The erosion characteristics of dense and porous W-films deposited on Pd substrates were measured
under impact of mirror Penning discharge nitrogen plasma. It is shown that the erosion rate of high
porous tungsten films (up to 45% porosity) is similar to that for dense (1 – 3% porosity) tungsten
films. At the same time hydrogen permeation through porous tungsten films essentially higher than
for dense W coatings and in some cases it approaches to values as for bare Pd. The activation energies
of hydrogen permeability measured for two-layer Pd-W systems with high porosity are higher than
for dense W-films on Pd (15.44 kJ/mol and 12.8 kJ/mol, accordingly), but these values much lower
than the ones for bulk W under gas-driven permeation experiments. The possible reasons of such
erosion and permeation behavior are discussed.
Зміряні ерозійні характеристики щільних і пористих плівок вольфраму на паладії при дії азотної
плазми відбивних розрядів Пеннінга. Показано,
що швидкість ерозії високопористих плівок вольфраму (пористість близько 45%) практично не
відрізняється від такої для щільних плівок W (пористість 1 – 3%). У теж час проникнення водню
крізь високопористі плівки вольфраму багато вище, ніж крізь щільні покриття W і в деяких випадках величини проникності можуть бути близькі
до такої для Pd без покриття. Енергії активації
водневої проникності зміряні для двошарових
систем Pd-W з високою пористістю W вище, ніж
для щільних W-плівок на Pd (15,44 кДж/моль і
12,8 кДж/моль, відповідно), але в обох випадках
ці величини багато нижче, ніж для масивного W
в умовах пронuкновения з молекулярної фази.
Обговорюються можливі причини такої поведінки ерозії і водневої проникності.
Измерены эрозионные характеристики плотных
и пористых пленок вольфрама на палладии при
воздействии азотной плазмы отражательных разрядов Пеннинга. Показано, что скорость эрозии
высокопористых пленок вольфрама (пористость
около 45%) практически не отличается от таковой
для плотных W пленок (пористость 1 – 3%). В
тоже время проникновение водорода через высокопористые пленки вольфрама много выше, чем
через плотные W покрытия и в некоторых случаях величины проницаемости могут быть близки к таковой для Pd без покрытия. Энергии активации водородопроницаемости измереннные для
двухслойных Pd-W систем с высокой пористостью W выше, чем для плотных W-пленок на Pd
(15,44 кДж/моль и 12,8 кДж/моль, соответственно), но в обоих случаях эти величины много ниже, чем для массивного W в условиях проникновения из молекулярной фазы. Обсуждаются возможные причины такого поведения эрозии и
водородопроницаемости.
|
| first_indexed | 2025-12-07T15:17:35Z |
| format | Article |
| fulltext |
ФІП ФИП PSE, 2006, т. 4, № 3 – 4, vol. 4, No. 3 – 4174
INTRODUCTION
It was reported in [1] that an erosion coefficient
of vacuum-plasma deposited (VPD) and che-
mical vapor deposited (CVD) dense W-films on
Pd is near to that for bulk tungsten, but hydrogen
permeability of such two-layer systems is much
lower (up to two orders of magnitude for CVD
W-films) than for bare palladium. To create more
effective diffusion system, it is needed to increase
hydrogen penetration through W films and the
increasing their porosity is the possible way for
this. It was also presented in [1] the effect of the
W erosion rate decrease in 2 – 5 times under
nitrogen plasma impact for Pd-W system in hyd-
rogen saturated state, in compare with non-sa-
turated state. It has been suggested to explain
such effect by selective hydrogen sputtering. To
confirm the reality of such mechanism it was ne-
cessary to examine the erosion behavior of such
diffusion system under impact of plasma dis-
charges in nitrogen-hydrogen mixtures, the more
so as such discharges have perspective to be used
for wall conditioning in plasma devices [2]. So,
in this work it were studied the influence of po-
rosity and hydrogen admixture to nitrogen on an
erosion behavior of W films on Pd and the influ-
ence of porosity on kinetics of hydrogen penet-
ration through such two-layer systems.
EXPERIMENTAL AND RESULTS
The experimental setup used in the erosion ex-
periments was the device DSM-1 [3,] with stea-
dy state mirror Penning discharge, which was
ignited at magnetic field 0.05 T and at work gas
pressure about 0.2 Pa. Plasma characteristics
measured by multigrid and single Langmuir pro-
bes (central and peripheral discharge regions, ac-
cordingly) are presented in tabl. 1, where U is
discharge voltage, I is discharge current, Te and
ne are electron temperature and electron density,
ϕ is plasma potential, Ei – ion energy for ma-
ximum of distribution function, ∆Ei – half-width
of distribution function.
UDC 621.385, 533.15
INFLUENCE OF POROSITY ON EROSION BEHAVIOR AND HYDROGEN
PERMEABILITY OF TUNGSTEN FILMS
G.P. Glazunov*, A.A. Andreev*, D.I. Baron*, M.N. Bondarenko*, R.A. Causey**,
A.M. Hassanein***, A.L. Konotopskiy*, I.M. Neklyudov*, I.K. Tarasov*, E.D. Volkov*
*
National Science Center “Kharkov Institute of Physics and Technology”
Ukraine
**Sandia National Laboratories, Livermore
USA
***Argonne National Laboratory, Argonne
USA
Received 25.10.2006
The erosion characteristics of dense and porous W-films deposited on Pd substrates were measured
under impact of mirror Penning discharge nitrogen plasma. It is shown that the erosion rate of high
porous tungsten films (up to 45% porosity) is similar to that for dense (1 – 3% porosity) tungsten
films. At the same time hydrogen permeation through porous tungsten films essentially higher than
for dense W coatings and in some cases it approaches to values as for bare Pd. The activation energies
of hydrogen permeability measured for two-layer Pd-W systems with high porosity are higher than
for dense W-films on Pd (15.44 kJ/mol and 12.8 kJ/mol, accordingly), but these values much lower
than the ones for bulk W under gas-driven permeation experiments. The possible reasons of such
erosion and permeation behavior are discussed.
Discharge
voltage and
current
Edge plasma characte-
ristics for porous/dense
cathodes
Central plasma
characteristics
U,
keV
I,
mА
ne⋅1010 ,
part./cm3 Te⋅104, К ϕ,
B
Ei,
eV
∆Ei,
eV
0.8 0.8 0.03/0.1 0.62/0.90 9/7 0.62 50
1 2.2 0.05/0.15 0.48/0.71 12/9 0.85 60
1.2 5 0.13/0.17 0.37/0.67 12/13 0.93 75
1.5 8 0.15/32 0.32/0.52 15/13 1.15 93
1.7 10 0.22/65 0.30/0.35 14/15 1.32 110
2 16 0.31/93 0.30/0.28 16/16 1.57 132
Table 1
Nitrogen plasma characteristics in
discharges with porous W cathodes
ФІП ФИП PSE, 2006, т. 4, № 3 – 4, vol. 4, No. 3 – 4 175
The samples for studies were W films vacu-
um-plasma deposited on palladium foils of
25mm diameter (for erosion experiments) or on
the 99.98% pure Pd tubes of 6 mm diameter,
0.25 mm thickness and 190 mm length (for per-
mea-tion studies). To produce dense tungsten
coatings (1 – 3% porosity), the deposition was
carried out at high vacuum or at argon pressure
lower than ≈0.6 Pa. The porous W-coatings
(about of the 45% porosity) were deposed at
argon pressure higher than 10 Pa. Coating thick-
nesses were measured by two different methods:
by weighting of probes before and after deposi-
tion and by optical measurements on metallo-
graphic sections. Porosity level was estimated
as the difference among thicknesses determined
by different methods. Metallographic and elect-
ron microscope investigations show the large
number of pores in tungsten films (fig. 1).
Erosion coefficient values were measured by
weight loss method reviewed in details in [1, 3].
The main results on erosion are presented in
fig. 2 and fig. 3. It is seen, that erosion rate of
porous tungsten films is similar to that for dense
tungsten films prepared by W sputtering in high
vacuum and that W erosion rate weakly depends
on hydrogen admixture to nitrogen up to 40%
concentration (fig. 3).
The scheme and methods of hydrogen per-
meation experiments were similar to the used
in the previous works [1, 3]. The dependencies
of specific hydrogen flow (permeation rate) ϕ
through membrane on inlet hydrogen pressure p
and on membrane temperature T are shown in
fig. 4 and fig. 5. From the data of temperature
dependencies of hydrogen permeation, the acti-
vation energy values E of hydrogen permeability
were calculated to be for two-layer Pd-W systems
with high tungsten porosity E = 15.44 kJ/mol
(for 9 µm and 14 µm W film thickness). This
value of activation energy is higher that for bare
palladium (11 kJ/mol) and higher than for dense
VPD 4µ W-films (11 kJ/mol). But, in any case,
Fig. 1. The metallographic microscopic sections (left, cen-
ter – before and after annealing) and surface morphology
(right) of 15 µm W film deposited at Ar pressure of
10.4 Pa.
Fig. 2. Erosion coefficient dependence on nitrogen ion
energy for Pd-W systems: � – dense W film, o – W film
of the 45% porosity, � – experimental data for hydrogen
saturated W films [2].
Fig. 3. Tungsten erosion coefficient versus nitrogen
concentration in hydrogen: experimental data for 1.2 keV
ion irradiation (o), curve is the calculated data.
Fig. 4. Hydrogen permeation rate at 973 K temperature
versus pressure: bare palladium (�); high porous 14 µm,
9 µm W film on Pd (�, �); 4 µm dense W film on Pd (o).
G.P. GLAZUNOV, A.A. ANDREEV, D.I. BARON, M.N. BONDARENKO, R.A. CAUSEY, A.M. HASSANEIN, A.L. KONOTOPSKIY ...
ФІП ФИП PSE, 2006, т. 4, № 3 – 4, vol. 4, No. 3 – 4176
the values of activation energy of hydrogen
permeation through W-Pd bimetallic systems are
much lower than the one (131.67 kJ/mol) for the
bulk W under gas-driven permeation experi-
ments reviewed in [4].
DISCUSSION
High porous materials have usually very exten-
ded surface, so higher erosion rate would have
been expected for high porous tungsten films due
to possible angle dependence of erosion. More-
over, heavy gas argon could be adsorbed in pores
and it could influence on the erosion rate. The
absence of an essential influence of W porosity
on its erosion behavior (fig. 2) is very encou-
raging result for creation of plasma facing diffu-
sion system. To explain such erosion behavior
one can to suppose the strong influence of rede-
position processes, when large number of sput-
tered tungsten atoms deposits on nearest surfaces
of W film pores. Note also, that the preliminary
measurements of outgassing from high porous
Pd-W systems have shown the absence of argon
release.
It is seen in fig. 3, that the sputtering weakly
depends on hydrogen admixture to nitrogen up
to the 40% concentration. Such dependence can
be easily explained on the base of mass depen-
dence of erosion rate, according to equation [3]:
α = α(H+)⋅IH/I + α(N+)⋅IN/I, where α(H+) and
α(N+) are the erosion coefficients under hydrogen
and nitrogen ion bombardment, respectively; I
is the total ion current; IH and IN are hydrogen
and nitrogen ion currents, respectively. If to
suppose that ion currents are proportional to gas
partial pressures, and to take into account that
α(H+)∼ 0.01 [5] we will obtain the curve in fig. 3
which is in close agreement with the experi-
mental points. The visible deviation for pure hyd-
rogen is explained by impurity flow from catho-
des during initial stage of discharges as it is ear-
lier shown in [3].
So, hydrogen addition to the main working
gas (nitrogen) could not be the reason for repor-
ted in [1] and above mentioned effect of an ero-
sion coefficient decrease of hydrogen saturated
W. And the physical mechanism, suggested in
[1] to explain this effect, is, most likely, hydro-
gen selective sputtering, similar to the reported
in [6] for deuterium saturated lithium under
helium ion bombardment.
Hydrogen permeation flow through W-Pd
membranes is near to j(P) ∼ P0.5 for both dense
and porous W-films (see fig. 4). But the unusual
film thickness dependence of hydrogen flow is
observed: hydrogen flow through 14 µm tungsten
layer is higher than through W film of 9 µm
thickness. It could be explained by the fact that
not only film open porosity increases with thic-
kness increase due to Lifshits-Slyozov-Wagner
pore coalescence theory [7, 8], but the porosity
of the initial coating layers increases with the
deposition time duration increase. The latter se-
ems as unlikely. At the same time the change of
film-Pd interface state can take place at the
increase of film thickness and heating time inc-
rease. Investigations of substrate-film interface
have shown that transition layer forms of W solid
solution in Pd in Pd-W samples produced at more
than 873 K (see fig.1). The additional heating
can change transition layer state (width, compo-
sition, etc.) and can lead to increase of its role in
hydrogen permeation process. Note, the preli-
minary investigations of the influence of long
time baking of dense W-films on hydrogen per-
meation rate have shown its essential (up to one
order magnitude) increase with baking time inc-
rease [fig. 6]. The activation energy values inc-
rease, too.
Hydrogen flows through porous W-films es-
sentially higher than for micron dense coatings
(fig. 4, fig. 5). For 14 µm porous W film the
hydrogen permeation rate at high temperatures
can be near to that for bare Pd. To recognize the
Fig. 5. Temperature dependencies of specific hydrogen
flow through two-layer Pd-W systems at 105 Pa H2 pres-
sure: bare palladium (�); high porous 14 µm and 9 µm W
film on Pd (�, �); 4 µm dense W film on Pd (o).
INFLUENCE OF POROSITY ON EROSION BEHAVIOR AND HYDROGEN PERMEABILITY OF TUNGSTEN FILMS
ФІП ФИП PSE, 2006, т. 4, № 3 – 4, vol. 4, No. 3 – 4 177
physical reasons for such extremely high hydro-
gen flows it is necessary to determine the limi-
ting stage of hydrogen penetration. It was ana-
lyzed and reported in previous work [1] that hyd-
rogen diffusion in rather dense micron W films
is the limiting stage of permeation process in
Pd-W two-layer systems. Very low values of acti-
vation energy were explained by the two reasons:
(i) the inverse dependence of hydrogen concen-
tration on the Pd-W interface and (ii) the anoma-
lous hydrogen diffusion along the network for-
med by communicating pores. The former pro-
vides the significant increase of hydrogen pres-
sure on the inlet side of W-film with temperature
decrease and strongly influences on the tempe-
rature dependence of hydrogen permeability and,
correspondingly, on flow and activation energy
values. The latter reduces barrier height for dif-
fusing atoms and also causes the activation ener-
gy decrease. Aforesaid reasons can act on hydro-
gen permeability of Pd-W system with high po-
rous W film, too. Film porosity increase and,
especially, open porosity increase provides high
hydrogen flows through such films. In this case
diffusion in W film can not be the limiting stage,
taking also into account the observed permeation
inverse dependence on film thickness. Hydrogen
solution in Pd and diffusion in Pd bulk can not
also be the limiting stage. So the diffusion in
transition layer on the Pd-W interface could be
the limiting stage. If so, one can explain high
hydrogen permeation with film thickness and
heating time increase as “interface opening”. Re-
ally, it is likely to suppose that an interdiffusion
during baking leads to increase of transition layer
width, and to enhancing of its role in permeation
process. Of course, in order to get a direct eviden-
ce of such mechanism favorability, additional in-
vestigations are needed.
If to analyze the results on Pd-W system ero-
sion behavior together with the data on hydrogen
permeation, it is came into clear that high porous
tungsten films are very convenient material for
plasma facing diffusion system creation. Being
of high erosion resistant, such films can provide
high hydrogen flows through them. These pro-
perties could be useful not only for hydrogen re-
cycling control but for tungsten erosion decrease
and tritium extraction in future fusion systems.
CONCLUSION
Erosion coefficients of porous vacuum-plasma
deposited W films on palladium are similar to
that for dense VPD tungsten films, and there is
not essential influence of W porosity on its ero-
sion behavior. It could be caused by the strong
influence of redeposition processes, when large
number of sputtered tungsten atoms redeposes
on nearest surfaces of W film pores.
Hydrogen admixture to nitrogen (up to 40%
atom.) does not essentially influence on the W
erosion rate. This confirms the hydrogen selec-
tive sputtering as the main physical mechanism
explaining the early observed effect of W ero-
sion coefficient decrease in hydrogen saturated
Pd-W system.
Hydrogen permeation rate through Pd-W
systems with high-porous W-films and activation
energy of hydrogen permeability for such sys-
tems are higher than for Pd-W two-layer systems
with dense W coatings. These results could be
explained if to suppose the diffusion in transition
layer on the Pd-W interface as the limiting stage
of Pd-W two-layer system permeation process.
ACKNOWLEDGMENTS
This work was supported by the Science and
Technology Center in Ukraine, project # 3134.
REFERENCES
1. Glazunov G.P., Andreev A.A., Baron D.I., Cau-
sey R.A., Hassanein A.M., Kitayevskiy K.M.,
Konotopskiy A.L., Lapshin V.I., Neklyudov I.M.,
Patokin A.P., Surkov A.E., Volkov E.D.//Fusion
Engineering and Design.– 2006. –Vol. 81. –
P. 375.
Fig. 6. Hydrogen permeation rate measured at 973 K tem-
perature and at hydrogen pressure of 105 Pa versus time
of baking at 973K temperature: � – 4 µm VPD W-film on
Pd, o – 300 µm CVD W-film on Pd.
G.P. GLAZUNOV, A.A. ANDREEV, D.I. BARON, M.N. BONDARENKO, R.A. CAUSEY, A.M. HASSANEIN, A.L. KONOTOPSKIY ...
ФІП ФИП PSE, 2006, т. 4, № 3 – 4, vol. 4, No. 3 – 4178
2. Glazunov G.P., Volkov E.D., Baron D.I., Kono-
top P.I., Lozin A.V., Tsybenko S.A.//Problems
of Atomic Scince and Technology, Series
“Plasma Physics”. – 2005. – Vol. 1. – P. 33.
3. Glazunov G.P., Volkov E.D., Baron D.I., Dol-
giy A.P., Konotopskiy A.L., Hassanein A.//Phy-
sica Scripta. – 2003. – Vol. 103. – P. 89.
4. Perkins W.G.//J. Vac. Sci. Technol. – 973. –
Vol. 10, No. 4. – P. 543.
ВЛИЯНИЕ ПОРИСТОСТИ НА
ЭРОЗИОННОЕ ПОВЕДЕНИЕ И
ВОДОРОДОПРОНИЦАЕМОСТЬ ПЛЕНОК
ВОЛФРАМА
Г.П. Глазунов, A.A. Aндреев, Д.И. Барон,
M.Н. Бондаренко, R.A. Causey,
A.M. Hassanein, A.Л. Koнотопский,
И.М. Неклюдов, И.К. Тарасов, E.Д. Волков
Измерены эрозионные характеристики плотных
и пористых пленок вольфрама на палладии при
воздействии азотной плазмы отражательных раз-
рядов Пеннинга. Показано, что скорость эрозии
высокопористых пленок вольфрама (пористость
около 45%) практически не отличается от таковой
для плотных W пленок (пористость 1 – 3%). В
тоже время проникновение водорода через высо-
копористые пленки вольфрама много выше, чем
через плотные W покрытия и в некоторых слу-
чаях величины проницаемости могут быть близ-
ки к таковой для Pd без покрытия. Энергии акти-
вации водородопроницаемости измереннные для
двухслойных Pd-W систем с высокой пористо-
стью W выше, чем для плотных W-пленок на Pd
(15,44 кДж/моль и 12,8 кДж/моль, соответствен-
но), но в обоих случаях эти величины много ни-
же, чем для массивного W в условиях проникно-
вения из молекулярной фазы. Обсуждаются воз-
можные причины такого поведения эрозии и
водородопроницаемости.
ВПЛИВ ПОРИСТОСТІ НА ЕРОЗІЙНУ
ПОВЕДІНКУ І ВОДНЕВУ ПРОНИКНІСТЬ
ПЛІВОК ВОЛЬФРАМУ
Г.П. Глазунов, A.A. Андрєєв, Д.І. Барон,
M.Н. Бондаренко, R.A. Causey
A.M. Hassanein, О.Л. Koнотопський,
І.М. Неклюдов, І.К. Тарасов, Є.Д. Волков
Зміряні ерозійні характеристики щільних і порис-
тих плівок вольфраму на паладії при дії азотної
плазми відбивних розрядів Пеннінга. Показано,
що швидкість ерозії високопористих плівок воль-
фраму (пористість близько 45%) практично не
відрізняється від такої для щільних плівок W (по-
ристість 1 – 3%). У теж час проникнення водню
крізь високопористі плівки вольфраму багато ви-
ще, ніж крізь щільні покриття W і в деяких випад-
ках величини проникності можуть бути близькі
до такої для Pd без покриття. Енергії активації
водневої проникності зміряні для двошарових
систем Pd-W з високою пористістю W вище, ніж
для щільних W-плівок на Pd (15,44 кДж/моль і
12,8 кДж/моль, відповідно), але в обох випадках
ці величини багато нижче, ніж для масивного W
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INFLUENCE OF POROSITY ON EROSION BEHAVIOR AND HYDROGEN PERMEABILITY OF TUNGSTEN FILMS
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| id | nasplib_isofts_kiev_ua-123456789-98795 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1999-8074 |
| language | English |
| last_indexed | 2025-12-07T15:17:35Z |
| publishDate | 2006 |
| publisher | Науковий фізико-технологічний центр МОН та НАН України |
| record_format | dspace |
| spelling | Glazunov, G.P. Andreev, A.A. Baron, D.I. Bondarenko, M.N. Causey, R.A. Hassanein, A.M. Konotopskiy, A.L. Neklyudov, I.M. Tarasov, I.K. Volkov, E.D. 2016-04-17T19:44:19Z 2016-04-17T19:44:19Z 2006 Influence of porosity on erosion behavior and hydrogen permeability of tungsten films / G.P. Glazunov, A.A. Andreev, D.I. Baron, M.N. Bondarenko, R.A. Causey, A.M. Hassanein, A.L. Konotopskiy, I.M. Neklyudov, I.K. Tarasov, E.D. Volkov // Физическая инженерия поверхности. — 2006. — Т. 4, № 3-4. — С. 174–178. — Бібліогр.: 8 назв. — англ. 1999-8074 https://nasplib.isofts.kiev.ua/handle/123456789/98795 621.385, 533.15 The erosion characteristics of dense and porous W-films deposited on Pd substrates were measured under impact of mirror Penning discharge nitrogen plasma. It is shown that the erosion rate of high porous tungsten films (up to 45% porosity) is similar to that for dense (1 – 3% porosity) tungsten films. At the same time hydrogen permeation through porous tungsten films essentially higher than for dense W coatings and in some cases it approaches to values as for bare Pd. The activation energies of hydrogen permeability measured for two-layer Pd-W systems with high porosity are higher than for dense W-films on Pd (15.44 kJ/mol and 12.8 kJ/mol, accordingly), but these values much lower than the ones for bulk W under gas-driven permeation experiments. The possible reasons of such erosion and permeation behavior are discussed. Зміряні ерозійні характеристики щільних і пористих плівок вольфраму на паладії при дії азотної плазми відбивних розрядів Пеннінга. Показано, що швидкість ерозії високопористих плівок вольфраму (пористість близько 45%) практично не відрізняється від такої для щільних плівок W (пористість 1 – 3%). У теж час проникнення водню крізь високопористі плівки вольфраму багато вище, ніж крізь щільні покриття W і в деяких випадках величини проникності можуть бути близькі до такої для Pd без покриття. Енергії активації водневої проникності зміряні для двошарових систем Pd-W з високою пористістю W вище, ніж для щільних W-плівок на Pd (15,44 кДж/моль і 12,8 кДж/моль, відповідно), але в обох випадках ці величини багато нижче, ніж для масивного W в умовах пронuкновения з молекулярної фази. Обговорюються можливі причини такої поведінки ерозії і водневої проникності. Измерены эрозионные характеристики плотных и пористых пленок вольфрама на палладии при воздействии азотной плазмы отражательных разрядов Пеннинга. Показано, что скорость эрозии высокопористых пленок вольфрама (пористость около 45%) практически не отличается от таковой для плотных W пленок (пористость 1 – 3%). В тоже время проникновение водорода через высокопористые пленки вольфрама много выше, чем через плотные W покрытия и в некоторых случаях величины проницаемости могут быть близки к таковой для Pd без покрытия. Энергии активации водородопроницаемости измереннные для двухслойных Pd-W систем с высокой пористостью W выше, чем для плотных W-пленок на Pd (15,44 кДж/моль и 12,8 кДж/моль, соответственно), но в обоих случаях эти величины много ниже, чем для массивного W в условиях проникновения из молекулярной фазы. Обсуждаются возможные причины такого поведения эрозии и водородопроницаемости. This work was supported by the Science and Technology Center in Ukraine, project # 3134. en Науковий фізико-технологічний центр МОН та НАН України Физическая инженерия поверхности Influence of porosity on erosion behavior and hydrogen permeability of tungsten films Вплив пористості на ерозійну поведінку і водневу проникність плівок вольфраму Влияние пористости на эрозионное поведение и водородопроницаемость пленок волфрама Article published earlier |
| spellingShingle | Influence of porosity on erosion behavior and hydrogen permeability of tungsten films Glazunov, G.P. Andreev, A.A. Baron, D.I. Bondarenko, M.N. Causey, R.A. Hassanein, A.M. Konotopskiy, A.L. Neklyudov, I.M. Tarasov, I.K. Volkov, E.D. |
| title | Influence of porosity on erosion behavior and hydrogen permeability of tungsten films |
| title_alt | Вплив пористості на ерозійну поведінку і водневу проникність плівок вольфраму Влияние пористости на эрозионное поведение и водородопроницаемость пленок волфрама |
| title_full | Influence of porosity on erosion behavior and hydrogen permeability of tungsten films |
| title_fullStr | Influence of porosity on erosion behavior and hydrogen permeability of tungsten films |
| title_full_unstemmed | Influence of porosity on erosion behavior and hydrogen permeability of tungsten films |
| title_short | Influence of porosity on erosion behavior and hydrogen permeability of tungsten films |
| title_sort | influence of porosity on erosion behavior and hydrogen permeability of tungsten films |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/98795 |
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