Emanuel Tack
Synopsis
Winning the tribological contest using a Digital Twin for PVD coated applications – Surface Solution for Gears as an example
Emanuel Tack1, Theresa Huben1 and Vincent Hoffmann2
1 Oerlikon Surface Solutions AG, Branch Balzers, Iramali 18, 9496 Balzers, Liechtenstein; 2Tribo Technologies GmbH, Steinfeldstr. 5, 39179 Barleben, Germany
E-mail: emanuel.tack@oerlikon.com
The main objective of the project is to increase the efficiency of gears. In previous research projects such as FVA 393 I & II and FVA 585 I, II & III, it has been shown that functional carbon-based coatings on gear components can have a friction-reducing effect in the lubrication regime of boundary, mixed friction and in the regime of hydrodynamic lubrication. A reduction of the average gear friction coefficient by a maximum of 20% was demonstrated by coating spur gears with DLC (= Diamond Like Carbon). [1] [2] In the hydrodynamical lubrication regime, the effect is mainly based on the reduction of fluid friction. In this project work, it is shown how DLC coatings are specifically optimized for the use on gears in the gearbox regarding tribological performance. Since it is hardly possible to carry out tribometer tests on a curved tooth of a helical gear wheel in a model test, a flat specimen is used instead of a single tooth. This flat specimen is placed in a dummy gear and therefore experiences the same geometric shading effect during the coating process as would be the case with a tooth. The flat specimens were specifically adapted to the properties of the real gear components in terms of material, hardness process and roughness, which makes it possible to transfer the results obtained from the model tests to time-consuming and cost-intensive gearbox tests. With the help of SRV tribometer tests on flat specimens, the mechanical-technological performance of DLC coating variants could be determined. The result of the specifically optimized coating architecture and its mechanical-technological properties are high-performance DLC coatings for gears, which offer high wear protection from the gear dedendum to addendum, even in the lubrication regime of boundary lubrication. Building up a “Digital Twin” of substrate, coating and lubricant (TEHD simulation) helps to understand the wear mechanism inside a gear contact, which allows to improve the coating.
References
[1] Ziegltrum, A., Lohner, T., & Stahl, K. (2018). TEHL Simulation on the Influence of Lubricants on the Frictional Losses of DLC Coated Gears. Lubricants, 6(1), 17. https://doi.org/10.3390/lubricants6010017
[2] Bobach, L., Bartel, D., Beilicke, R. et al. Reduction in EHL Friction by a DLC Coating. Tribol Lett 60, 17 (2015). https://doi.org/10.1007/s11249-015-0594-2
Bio
- Since 2010 working in the field of DLC coatings, rolling bearings, gears and Tribology
- Since 2015 active member of the “German Society for Tribology”
- organizing “Young Tribological Researcher Symposia”
- Since 2019 Co-Organizer of the annual Swiss Tribology Symposia
- Since 2024 in the Program Committee of the annual “German Society for Tribology Symposia”
- Since 2024 in the candidature team for the World Tribology Conference 2030 Germany & Switzerland