ICMCTF 2012! - CD-Lab Application Oriented Coating Development

eactive gases with the target material. So, investigation was carried out the
effects of sputtering gases for the preparation of CNx films by RF reactive
sputtering. CNx films were prepared using RF magnetron sputtering
apparatus. Graphite was used as a target and Si was used as the substrate.
The substrate was pretreated to immerse on BHF for 5 minutes. RF power
and pressure were fixed to 200W and 0.4Pa, respectively. Ar and N2 were
used as sputtering gases and their ratio was Ar/N2=1/0, 1/1, 1/3, and 1/5.
The sputtering time was 60 minutes. The CNx films were prepared after
pre-sputtering using same condition for 10 minutes. The deposits were
estimated by using of SEM, XPS and Raman spectroscopy. From the crosssectional
SEM images, deposition rate was increased by adding of N2 to Ar
sputtering gas and floating substrate holder potential. As a result of Raman
spectroscopy, the DLC broad peak center around 1550cm-1, D-band peak
center around 1350cm-1, G-band peak center around 1580cm-1and S-band
peak center around 1200cm-1 were observed in spectra of each samples. As
a result of XPS, the peaks of C-C and -C=O bond were observed in C1s
spectra of the deposit prepared using Ar. The peaks of C-C, C=O, N=O-, C-
N, =C-N=C- and -C≡N bond were observed in C1s and N1s spectra used
mixture of Ar and N2 as sputtering gases. As mention above, the deposit
contain nitrogen was obtained using the mixture of Ar-N2 gases. As a result
of preparation of CNx films by RF reactive sputtering, DLC was obtained
using Ar as the sputtering gases. On the other hand, it was possible to
prepare CNx using the mixture of Ar and N2 gases as a sputtering gas.
9:00am B1-3-4 Zirconium carbonitrides: study of tribological
properties with deposition parameters, J. Barriga
(jbarriga@tekniker.es), L. Mendizabal, U. Ruiz de Gopegui, Tekniker,
Spain
In the last years a great effort has been done in the development of carbon
based coatings for tribological applications. As a consequence, the sliprolling
resistance of DLC thin films was improved considerably. On the
other side, zirconium has been used widely in the decorative industry
because of its corrosion resistance and wide range of affordable metallic
colors. But the use of Zr in tribological thin films is not very broad.
However, recent developments show that zirconium based coatings could
perform better than DLC thin films in tribological contacts under severe
contact conditions [1].
In the present work, zirconium carbonitride thin films have been developed
on M2 steel by cathodic arc evaporation under a wide range of deposition
parameters. BIAS voltage has been varied from 30 to 400 V. Temperature
during the process has also been controlled from 500ºC to 300ºC, in order to
study the possibility of doing the deposition at low temperatures opening
the range of substrate steels. Finally, the flux of acetylene gas has also been
varied to study the influence of carbon content in the properties of the film.
A wide characterization procedure has been taken with the resulting ZrCN
coatings: Calotest, SEM, X-Ray analysis, adhesion tests and, finally, a
battery of sliding tribological tests. With this we have analyzed the
influence of deposition parameters on the films and looking for the proper
applications of the best performing films.
[1] Charles-Alix Manier, Holger Ziegele, Javier Barriga, Josu Goikoetxea,
Mathias Woydt, Zirconium-based coatings in highly stressed rolling
contacts as alternative solution to DLC and ta-C coatings, Wear 269 (2010)
770–781.
9:20am B1-3-5 Comparison of sputter deposited WC coatings from
alternative sources, H. Alagoz (alagoz@bilkent.edu.tr), E. Uzun, M.
Ugras, N. Uddin, E. Bengu, Bilkent University, Turkey
Transition metal nitride and carbide coatings attracted a lot of attention in
the last decades due to their good wear, erosion, corrosion and high
temperature oxidation resistance. In this study, an alternative synthesis
approach was used for the synthesis of carbide coatings in the W-C system.
New WxCy coatings were synthesized by reactive magnetron sputtering
technique with various target combinations and gas compositions on
Si(100) and steel (100Cr6) substrates. Instead of the frequently used carbon
sources such as WC(1:1) or graphite target, and CH4 or C2H2 gases, a B4C
target was used as an alternative for C source and N2 gas was fed through
the chamber during deposition. For comparison, another set of coatings
were synthesized using an additional graphite target together with allowing
C2H2 gas feed instead of N2 flow in order to see the effect of increasing C
content in the coatings. We investigated the change in the phase
composition, chemical bonding, hardness, room-temperature and hightemperature
wear rates of these two sets of coatings. Scanning electron
microscopy (SEM) was used to understand the effect of process parameters
on surface roughness and microstructure of the films. The hardness values
of the films were measured using the nano-indentation technique and, we
used a high-temperature tribometer (up to 800°C) to investigate the wearrates
of the coatings. X-ray photo-electron spectroscopy (XPS) has been
employed to understand the bonding states of tungsten and carbon as well
as boron, nitrogen and oxygen on the as-deposited surfaces. Our results
showed that the coatings are mostly combinations of W+WC, W+W2C and
BN in the case of N2 flow. Coatings containing BN species are showing
considerably good hardness (up to 31.5 GPa) and wear performances(up to
2.0x10 -7 mm 3 /Nm at room-temperature and 2.0x10 -6 mm 3 /Nm at 500 o C).
Increasing the C content of the films in the second set of experiments did
not cause a significant change on the wear rates but gave a gradual decrease
to the hardness and friction coefficient of the films.
9:40am B1-3-6 The influence of the magnetic field strength on the
poisoning behavior of Tantalum, R. Hollerweger
(robert.hollerweger@unileoben.ac.at), Montanuniversität Leoben, Austria,
M. Lechthaler, OC Oerlikon Balzers AG, Liechtenstein, P. Polcik,
PLANSEE Composite Materials GmbH, Germany, J. Paulitsch, P.H.
Mayrhofer, Montanuniversität Leoben, Austria
Reactive magnetron sputtering requires precise knowledge of the chemical
and physical processes in the plasma itself as well as at the target surface.
Therefore, a lot of investigations are focusing on the poisoning behavior in
dependency of parameters like power density, reactive gas partial pressure,
total pressure or magnetic field configuration. Especially the change of the
magnetic field strength due to progressing target erosion has a pronounced
influence on the target poisoning as well as plasma conditions and hence, on
the plasma and film properties. To investigate this effect, voltage hysteresis
curves were recorded while sputtering a Ta target in Ar-O2 atmosphere. The
magnetic field strengths and DC current densities were subsequently varied
from 45 to 90 mT and from 13 to 26 mA/cm², respectively. Due to these
variations, a shift of the different sputtering regimes within the hysteresis
can be detected. Selected points, referring to oxygen gas contents of 42, 70
and 100 % of the total gas flow, were used for the deposition and
characterization of Ta2O5 thin films, which indicate hardness values in the
range of 15 GPa, crystalline structure and high thermal stability. This
comprehensive study of the sputtering behavior helped to gain well-founded
knowledge of possible influences on the poisoning behavior of Tantalum as
well as on the film formation processes of the resulting pentoxide.
10:00am B1-3-8 Cavitation and abrasion resistance of Ti-Al-Y-N
coatings prepared by the PIII&D technique from filtered vacuum-arc
plasma, V. Belous, V. Vasyliev, A. Luchaninov, V. Marinin, E. Reshetnyak,
V. Strel’nitskij, National Science Center “Kharkov Institute of Physics and
Technology”, Ukraine, S. Goltvyanytsya, V. Goltvyanytsya
(vladtnt@gmail.com), Real Ltd., Ukraine
Ti-Al-Y-N coatings with small Y percentage have demonstrated high
hardness and excellent oxidation resistance which provides their application
for protection the machine parts which operate under extreme
environmental conditions. In our recent work [1] we investigated structure
and properties of such coatings prepared by the plasma immersion ion
implantation and deposition (PIII&D) using filtered vacuum-arc plasma
source.
Deposition from the filtered vacuum arc plasma is the widely used effective
method of manufacturing high quality protective wear resistant coatings. A
high-voltage pulsed bias applied to the substrate permits the deposition of
thicker coatings with good adhesion and low residual stresses. In the present
work we examined the cavitation and abrasion resistance of PIII&D
deposited Ti-Al-Y-N coatings doped with yttrium (≤ 1 at.%) and analyzed
correlation between their properties and structure.
Ti-Al-Y-N coatings with thickness of 5-6 micron were deposited on the 302
stainless steel substrates from filtered vacuum-arc plasma at nitrogen
pressure of 0.1 Pa. Ti0.5-xAl0.5Yx alloys (x = 0, 0.002, 0.004 and 0.01)
produced by vacuum-arc remelting in argon atmosphere (by Real Ltd.,
Zaporozhye, Ukraine) were used as cathodes in the vacuum-arc plasma
source. The substrate potential was either DC (-150 V) or negative pulsed,
the amplitude AU varied in the range of 0-2.5 kV.
The erosion resistance of the coatings was evaluated on the measured mass
loss during cavitation treatment in distilled water. The tests were continued
until visually watched open-ended pores in the coating were formed.
Abrasion wear was determined in the scheme substrate plane – rotating
abrasion disk.
The substrate potential during deposition process and Y content in the
coatings were found to be important factors influencing the rate and
character of their cavitation damage. The coating deposited at AU=0 was
subjected to pitting erosion. Long cracks prevailed on the surface of the
cavitation treated coating deposited at DC (-150 V) potential. High voltage
pulsed substrate potential contributed to decrease by 3-5 times in the rate of
the mass loss under cavitation, quantity of the erosion defects on the treated
surface diminishes sharply. Increase of Y content resulted in improvement
of wear durability. Mean rates of cavitation and abrasion wear of
(Ti,Al)N+1at.%Y were a factor of 3 to 5 times lower than that of (Ti,Al)N
and tenfold lower than that of TiN.
25 Tuesday Morning, April 24, 2012