ICMCTF 2012! - CD-Lab Application Oriented Coating Development

duration for super-low friction seems to be a big issue for its application.
DLC based nanocomposite coatings are promising to solve the problems. In
this work, pure DLC coatings on Ti-6Al-4V plates and Si wafers were
firstly investigated using direct ion beam deposition technique in order to
optimize the processing parameters. Then, nanocomposite coating samples
of DLC-MoS2 were deposited on the Ti-based substrate by a hybrid
technique of ion beam deposition and target biased ion beam sputtering.
The structure of the nanocomposite samples were investigated by Raman
Spectroscopy, X-ray photoelectron spectroscopy (XPS) and X-ray
diffraction (XRD). Their mechanical and tribological properties were
studied using nanoindentation, scratch testing, nanoanalyzer, and pin-ondisc.
The results show that the nanocomposite coatings have much
improved adhesion to the substrate and comparable hardness and
tribological properties with that of pure DLC coatings.
3:10pm B5-2-5 Growth of Amorphous Hf-Al-Si-N Thin Films by DC
Magnetron Sputtering, H. Fager (hanfa@ifm.liu.se), Linköping
University, IFM, Thin Film Physics Division, Sweden, A. Mei, University
of Illinois at Urbana-Champaign, US, B.M. Howe, Air Force Research
Laboratory, US, J.E. Greene, I. Petrov, University of Illinois at Urbana-
Champaign, US, L. Hultman, Linköping University, IFM, Thin Film
Physics Division, Sweden
Crystalline and nanocrystalline transition metal nitrides have attracted a lot
of interest over the years, and they are well known to have a wide range of
outstanding properties that makes them suitable in many different
applications. In comparison with crystalline transition metal nitrides, and
also compared to corresponding carbides and oxides, very little has been
reported on amorphous transition metal nitrides and most of their properties
are still unknown. Nevertheless they are potentially attractive, e.g., as wear
resistant coatings, due to their homogeneous structure. We propose
amorphous multicomponent transition metal nitrides as a new class of
refractory materials.
Using kinetically limited growth techniques - including low growth
temperatures and high deposition rates - is one of the keys to growing
amorphous transition metal nitride films. In this study, we investigate the
HfN-AlN-Si3N4 system, where the difference in atomic size and bond
coordination between the constituent elements, in combination with
kinetically limited growth, promotes the formation of an amorphous
structure. Hf1-x-yAlxSiyN thin films were grown on Si(001) substrates by
reactive magnetron sputtering from a single Hf0.6Al0.2Si0.2 target. We show
that we can control the film morphology, from nanocrystalline to
amorphous, by varying the ion flux and growth temperature, and also the
film composition by varying the ion energy.
Compositional analysis of the as-deposited films was performed by energy
dispersive x-ray spectroscopy (EDS), and the structural information was
gained by x-ray diffraction and analytical transmission electron microscopy.
We will report on hardness and elastic properties of the films, as well as
temperature dependent resistivity.
3:30pm B5-2-6 Nanocomposite coatings in the Al-Ge-N system:
synthesis, structure and mechanical and optical properties, E. Lewin
(erik.lewin@empa.ch), M. Parlinska-Wojtan, J. Patscheider, Empa,
Switzerland
Coatings in the Al-Ge-N system have been synthesized using reactive DC
magnetron sputtering and characterized with the goal to explore the
structure and properties, as well as their potential use as hard optical
coatings. The composition was varied from pure AlN to pure GeNy. Also
experiments varying substrate temperature and sample bias were conducted.
Coatings were analyzed using X-ray diffraction, X-ray photoelectron
spectroscopy (XPS) and scanning and transmission electron microscopy.
Besides the binary reference samples, ternary samples with Ge-contents
from 5 to 30 at.% were synthesized, and found to be nanocomposites of a
nanocrystalline, Ge-containing AlN-phase, nc-(Al1-xGex)N, and an
amorphous, N-deficient GeNy-phase. The grain size of the (Al1-xGex)N
phase decreased with increasing Ge-content from about 30 to 15nm.
Additionally the (Al1-xGex)N -phase was found to exhibit two different
textures depending on the Ge-content: at low Ge content a (001) preferred
orientation was observed, while at increased Ge-content the (110)
orientation became dominant. The GeNy phase was found to be highly
susceptible to sputter damage during sputter-cleaning prior to XPS analysis.
A nanocomposite-hardening, similar to what has been observed for e.g. the
AlN/Si3N4 system, was observed: the hardness increased from 19 GPa (for
the AlN reference sample) to 25 GPa for the hardest ternary sample.
Samples were found to have a high transparency in the visible region, and
the index of refraction shows a slight dependence of Ge-content, increasing
from about 2.0 to 2.2 as Ge-content increases from 0 to 30 at.%. Thus these
coatings have a potential use as protective coatings for optical components
operating in the visual or near IR range.
3:50pm B5-2-7 Shape- Recovery of Thin Film Metallic Glasses Upon
Annealing, C. Rullyani, C. Li, J. Chu (jpchu@mail.ntust.edu.tw), National
Taiwan University of Science and Technology, Taiwan
Thin film metallic glasses (TFMGs) possess many excellent and unique
properties, including high strength, ductility, annealing-induced
amorphization and good adhesion between the substrate and film. Like
ordinary metallic glasses, the TFMGs in general undergo the glass transition
and crystallization at temperatures of Tg and Tx, respectively, upon
annealing. Another exceptional property of TFMGs is the shape-recovery
ability during annealing at temperatures between Tg and Tx (or so-called the
supercooled liquid region, ΔT) due mainly to the low viscosity flow.
Surface defects such as indentation marks on the scales up to a few
micrometers tend to shrink in size or even disappear without crystallization
in ΔT.
In this study, 200 nm-thick TFMGs with different compositions are
deposited on Si substrates. Nanoindentation tests are performed to evaluate
the film properties. Surface morphology and microstructure before and after
annealing within ΔT are examined and reveal that the size of indentation
mark decreases after annealing. As a result, the shape-recovery behavior is
confirmed and detailed characterization results of various TFMGs as a
function of annealing time will be discussed.
Keyword: thin film metallic glass, annealing, shape recovery
4:10pm B5-2-8 Thin Film Metallic Glasses: Unique Properties and
Potential Applications, J. Chu (jpchu@mail.ntust.edu.tw), National
Taiwan University of Science and Technology, Taiwan INVITED
A new group of thin film metallic glasses (TFMGs) have been reported to
exhibit properties different from conventional crystalline metal films,
though their bulk forms are already well-known for the high strength and
toughness, large elastic limits, excellent corrosion and wear resistances
because of the amorphous structure. In recent decades, bulk metallic glasses
(BMGs) have gained a great deal of interest due to the substantial
improvements in specimen sizes. On the other hand, much less attention has
been devoted to the TFMGs, despite the fact that they have many properties
and characteristics which are not readily achievable with other types of
metallic or oxide films. Furthermore, these TFMGs have been progressively
used for engineering applications and thus deserve to be recognized in the
field of thin film coatings.
In addition, while the BMGs are still difficult to use because of their brittle
macroscopic nature and difficulty of processing, TFMGs are a possible
solution to make use of their great properties of high strength, large
plasticity, and excellent wear resistance. In this presentation, many
advantages and properties of TFMGs are discussed. These are such as
mechanical properties, tribological properties, annealing-induced
amorphization and resulting smooth surface, some of which lead to useful
applications, for example, for substrate fatigue property enhancements. In
addition, potential applications in microelectronics and optoelectronics are
mentioned. Ironically, there have been enormous research efforts dedicated
to developing metallic glasses with large critical sizes only to reveal that the
best use for these materials may, in fact, be in thin film applications. It is
thus hoped that this talk serves the purpose of calling attention to the
importance of TFMGs such that many more studies and applications may be
explored.
4:50pm B5-2-10 Improving the corrosion resistance and hardness of
TaN films by silicon addition, G. Ramírez (enggiova@hotmail.com), S.E.
Rodil, S. Muhl, G. Galicia, Universidad Nacional Autónoma de México -
Instituto de Investigaciones en Materiales, Mexico, E. Camps, L. Escobar-
Alarcón, Instituto Nacional de Investigaciones Nucleares de México,
México, D. Solis-Casados, Universidad Autónoma del Estado de México -
Centro de Investigación en Química Sustentable, Mexico
The aim of the present work was to obtain dense thin films that present
simultaneously good corrosion resistance and hardness. For this, we
propose the deposition of nanocomposite thin films where tantalum nitride
(TaN) nanocrystals were embedded in an amorphous silicon nitride (SiNx)
phase. The deposition was done using two magnetrons; one of pure Si and
the other of pure Ta and the amount of Si into the samples was varied by
changing the RF power (20 - 340 W) applied to the Si target. The N2/Ar
ratio was fixed at the value optimized for the stoichiometric deposition of
tantalum nitride films (6/14). The TaN-SiNx samples were deposited on
silicon and their composition, structure and hardness were evaluated by Xray
photoelectron spectroscopy, X.ray diffraction and nanoindentation,
respectively. The results indicated that the silicon content increased linearly
from 1 to 12 at% as the RF power was increased. Meanwhile, the hardness
showed a maximum around 5.4 at% of silicon attaining 40 GPa,
representing a 20 % hardness enhancement in comparison to the fcc phase
of the TaN film. From the structural analysis, it was observed that the TaN
d -fcc phase was stabilized due to the addition of Si. However, for the
65 Wednesday Afternoon, April 25, 2012