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Bingen am Rhein, Germany

Gies A.,Balzers Ag | Chudoba T.,ASMEC GmbH | Schwarzer N.,Saxonian Institute of Surface Mechanics SIO | Becker J.,Oerlikon Balzers Coating Germany GmbH
Surface and Coatings Technology | Year: 2013

In this work, homogeneous as well as gradient a-C:H:W coatings were deposited on a steel substrate. The mechanical properties of both coating systems were determined using nanoindentation. In addition, a multiaxial, 3-dimensional nanoindentation test (reciprocating wear test with nanometre resolution) was carried out in order to analyse the wear-performance of the two different coating systems.By comparing the wear-performance of the gradient coating system to the non-graduated one we were able to show that according to a theoretical approach proposed a few years ago the gradient coating systems lead to a better performance in micro-wear tests as well as in macro-scale wear tests.In addition, a new wear model taking into account the changing stress fields during the wear tests is proposed in order to simulate the wear behaviour of both coating systems. © 2013 Elsevier B.V.

Keferstein C.P.,University of Applied science Buchs | Marxer M.,University of Applied science Buchs | Gotti R.,University of Applied science Buchs | Thalmann R.,Federal Office of Metrology METAS | And 3 more authors.
CIRP Annals - Manufacturing Technology | Year: 2012

Reference spheres play an important role in the accuracy of multisensor coordinate measuring machine (CMM) applications. Nowadays there are a number of spheres specialized in the characteristics of different CMM probing systems. This paper presents a unique reference sphere which meets sometimes contradictory requirements of different measurement principles. With this sphere it is possible to qualify all probing systems widely used today. It is suitable for contacting and non-contacting probing systems such as vision systems, chromatic and laser probes and Computed Tomography. With this sphere, it is possible to achieve tactile probing errors of less than 1 μm. © 2012 CIRP.

Stein S.,Balzers Ag | Lechthaler M.,Balzers Ag | Krassnitzer S.,Balzers Ag | Albrecht K.,Balzers Ag | And 2 more authors.
Procedia CIRP | Year: 2012

In order to evaluate performance and wear of gear cutters and coatings, various analogy cutting tests are nowadays used. Since these state-of-the-art tests significantly differ in complexity and comparability to real dry hobbing applications, this work presents a critical literature comparison highlighting the different characteristics, and further introduces a new approach to adjust the appearing wear characteristics by a simple analogy testing method. Moreover, substrate softening of PM-HSS during the cutting process has been analyzed and related to the relevance of the thermal barrier effect of coatings. The results are confirmed by calculations of the temperature evolution within the coating-substrate compound at constant contact temperature. © 2012 The Authors.

Keunecke M.,Fraunhofer Institute for Surface Engineering and Thin Films | Bewilogua K.,Fraunhofer Institute for Surface Engineering and Thin Films | Becker J.,Oerlikon Balzers Coating Germany GmbH | Gies A.,Balzers Ag | Grischke M.,Balzers Ag
Surface and Coatings Technology | Year: 2012

Diamond-like carbon (DLC) coatings, especially amorphous hydrogenated a-C:H and metal containing a-C:H:Me coatings are well established in the automotive industry as standard solutions to eliminate wear problems of highly loaded components due to their outstanding properties in terms of low friction coefficients under dry conditions. Under lubricated conditions the friction can be reduced once more by applying lubricants with special additives. For example the friction modifier MoDTC (molybdenum-dithio-carbamate) is used in many engine oils. Metal free a-C:H coatings were found to interact in a negative way with MoDTC in high concentrations. In order to overcome these problems CrC/a-C:H coatings with different Cr contents were prepared by reactive magnetron sputtering, and tested systematically under lubricated conditions with and without MoDTC. The results were compared with those obtained for pure a-C:H. Hardness and abrasive wear were determined as a function of the Cr content and coating structure. With an increasing Cr content the morphology of the coatings became denser and the surfaces smoother. The hydrogen content in the coatings decreased continuously with increasing Cr contents and reached values close to 3. at% for chromium to carbon (Cr:C) ratios close to 1. Taking into account these hydrogen contents and sub-stoichiometric chromium carbide phases, a nanocomposite-like structure with chromium carbide phases embedded in an a-C:H binder matrix can be assumed. CrC/a-C:H coatings with Cr:C ratios in the range of 1, but having a notable amount of an amorphous a-C:H phase, showed to be an optimum solution under lubricated conditions with MoDTC because they exhibit both low friction and extremely low wear rates. The wear mechanism, especially the interaction with the friction modifier MoDTC will be discussed. © 2012 Elsevier B.V.

Trankenschuh B.,Oerlikon Balzers Coating Germany GmbH
Vakuum in Forschung und Praxis | Year: 2013

Before coating the surface of the component which shall be coated is cleaned. Several machines and chemicals can be used. After the cleaning the surface must be ready for coating. The influence of the machining parameters on the surface of a component is shown. The effectiveness of the cleaning processes prior to coating is discussed, and put in context to the whole manufacturing process. A classification of the manufacturing process should not be based on the different locations where it takes place. All the machining steps which influence the properties and the coat ability of the metal surface should be considered as connected. All these treatment steps are ideally tuned in a way that the surface can be coated flawlessly. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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