ICMCTF 2012! - CD-Lab Application Oriented Coating Development

This article describes how to use surface technology as a modern design
element for components and systems to enable the increasing requirements
on market leading automotive and industrial products.
Therefore Schaeffler has developed and established a coating tool box for
customized surfaces to apply the right solutions for all that needs and
requests with the corresponding coating system made by PVD-/ PACVD-,
spraying or electrochemical technology. For innovative products it is
extremely important that coatings are considered as design elements and
integrated in the product development process at a very early stage.
In this article tribological coatings are viewed within a holistic and designoriented
context. The latest developments of amorphous carbon coatings, its
characteristics as well as the technical and economical effects of its use in
combustion engines and industrial bearing applications are described.
The presented Triondur ® amorphous carbon based coating systems (a-C:H;
a-C:H:Me; a-C:H:X and ta-C) are excellent examples for customized
tribological systems like bucket tappets, linear guidances and roller
bearings.
Triondur ® carbon coatings offer the following advantages:
• Super low friction with highest wear resistance.
• Customized surface energy.
• Optimized wetability and interaction with formulated engine oils.
• Low adhesion to the counterpart.
Close collaboration between designers and surface engineers is required in
the future. Schaeffler delivers around 70 million high-quality PVD- and
(PA)CVD-coated components (Triondur ® ) every year that enable
outstanding applications, preserve resources and meet increasing customer
requirements.
3:50pm E3-2/G2-2-7 Ultra-fast Synthesis of Superhard Borides: A
Paradigm Shift in Surface Engineering for Tooling and Automotive
Applications, A. Erdemir (erdemir@anl.gov), O.L. Eryilmaz, Argonne
National Laboratory, US, S. Timur, Istanbul Technical University, Turkey,
O. Kahevcioglu, Argonne National Laboratory, US, G. Kartal, Istanbul
Technical University, Turkey, V. Sista, Argonne National Laboratory, US
During the last two decades, there has been considerable interest in the
development and diverse utilization of novel coatings and surface
treatments that can enhance efficiency, durability, and environmental
compatibility of a variety of automotive and machine tool components.
Among others, the development of DLC and other low-friction coatings has
attracted the most attention mainly because of their unique abilities to
provide much superior performance under severe tribological conditions.
Tribological properties of mechanical components can also be improved by
a variety of well-established surface treatments like nitriding, carburizing,
and boriding. All of these methods are used extensively by today’s
automotive industry despite being very time and energy consuming. In this
talk, a novel super-fast surface treatment method called ultra-fast boriding
will be introduced as a highly robust and low-cost alternative to current
surface treatment and coating methods. New boriding process is capable of
producing more than 90 micrometer thick boride layers in 30 minutes on a
variety of steels and in the case of certain non-ferrous alloys, it is capable of
producing ultra-thick and hard boride layers providing more than 45 GPa
hardness. The primary focus of this talk will be on the chemical, structural,
and mechanical design of such boride layers for severe operating conditions
of various engine and tooling applications. Initial test results from a variety
of bench-top tribotest machines will also be presented to demonstrate the
much superior tribological properties for such boride layers over a broad
range of test conditions.
4:10pm E3-2/G2-2-8 A study on tribological behavior of arc-coated Ti-
Al-N films on AISI 4340 alloy steel for automotive application, C. Hsu,
Tatung University, Taiwan, C. Lin (cklin@fcu.edu.tw), Feng Chia
University, Taiwan, D.W. Lai, Tatung University, Taiwan, K. Ou, Taipei
Medical University, Taiwan
This study utilized cathodic arc evaporation method to coat Ti-Al-N films
on AISI 4340 steel for evaluating the feasibility of prolonging the use-life in
the application of landing gears and truck parts. SEM, XRD, and TEM were
used to confirm the morphology and structure of the coatings, and some
coatings properties, such as adhesion, hardness, Young’s modulus, residual
stress, and friction coefficient were all analyzed. The results showed that
TiAlN film was indeed a single phase of FCC structure. The TiN/TiAlN
multi-layered films had a good adhesion (HF1), high hardness (36.5 GPa),
Young’s modulus (461 GPa), and appropriate residual stress (-5.68 GPa).
Moreover, the optimum coatings achieved a remarkable reduction in the
steel friction coefficient from 0.81 to 0.45.
4:30pm E3-2/G2-2-9 Predicting lifetime of silver and gold coating
depending on their thickness, stress and environmental conditions, O.P.
Perrinet (olivier.perrinet@ec-lyon.fr), LTDS, France
The fretting wear phenomenon in electrical contacts is a plague in many
applications, especially in the automotive industry, but also in other
machines exposed to vibration. It induces severe electrical distortions, high
electrical contact resistance and micro cuts.
This has led to the development of numerous coating systems consisting of
pure metallic materials, noble and non-noble, doped as well as soft coatings.
Five coating systems were studied: a bronze–nickel–with different types of
doped silver coating system and a bronze–nickel–with different types of
doped gold coating system.
Using this apparatus, most of the physical conditions, such as relative
humidity, temperature, frequency, relative displacement and normal force,
can be precisely controlled and monitored.
We have observed and understood the kinetics of wear in connection,
disconnection and reconnection simulation of electrical connector. This
approach is applied to analyze hard coating wear mechanisms focusing on
abrasion and oxidation phenomena.
4:50pm E3-2/G2-2-10 Understanding durability of lubricant/DLC
coating interface, L. Austin, T. Liskiewicz (t.liskiewicz@leeds.ac.uk), A.
Neville, Leeds University, UK, R. Tietema, Hauzer Techno Coating, BV,
Switzerland
DLC coatings are recognised as a promising way to reduce friction and
increase wear performance of automotive parts and are currently being
introduced for some engine and transmission components. DLC coatings,
especially hydrogenated and doped with W or Si DLC coatings, provide
new possibilities in improving tribological performance of automotive
components, beyond what normally can be achieved with lubricant design
only. However, currently used lubricants have been originally designed for
metallic surfaces and there is a lack of knowledge on tribological behaviour
of DLC coatings when lubricated with these oils, which limits their use in
practical applications.
In this project, a W doped DLC coating is tested in lubricated contact
simulating the engine tap/follower interface. The role of lubricant/surface
interactions is investigated experimentally against a steel counterface. The
tribofilm formation process is characterized chemically and mechanically
using EDX mapping, XPS and nanoindentation. A link between the
tribofilm structure/composition and tribological performance is studied.
Hardness and elastic modulus are mapped within the contact area showing
the evolution of the tribofilm mechanical properties. The f riction process is
related to the dynamics of tribofilm formation and tribofilm time
dependence is investigated. The emphasis of the paper is on how the coating
structure and composition can be adapted for optimal interaction with fully
formulated lubricant to enhance the tribological “system” performance.
5:10pm E3-2/G2-2-11 From DLC to Si-DLC based layer systems with
optimized properties for tribological applications, D. Hofmann
(dieter.hofmann@amg-ct.de), S. Kunkel, AMG Coating Technologies
GmbH, Germany, K. Bewilogua, R. Wittorf, Fraunhofer IST, Germany
Diamond-like carbon (DLC) coatings are used in many industrial
applications like valvetrain-, fuel injection- and piston-systems etc.. For
DLC (a-C:H) coatings, prepared by a magnetron based technique using
graphite targets, high indentation hardness values of more than 40GPa were
achieved. The wear resistance, the microhardness and the coefficient of
friction are shown as a function of the hydrogen concentration in the
coatings. In order to reduce the coefficient of friction even more and to
increase the operation temperature of the coatings from about 350°C for
DLC to near 500°C, a new Si-DLC based layer system was developed using
a special magnetron sputter target configuration. This Si-DLC based layer
system combines the benefits of a reduced coefficient of friction with a high
wear resistance. The DC magnetron based production method allows the
deposition of Si-DLC coatings in a wide range of compositions with 5 to 25
at.% Si at low hydrogen contents down to 5 at.%. The new Si-DLC based
coatings show favorable conditions for present and future industrial
applications.
45 Tuesday Afternoon, April 24, 2012