Optimization of Tribosystems Through the Combination of Experimental and Numerical Approaches

Observing friction and wear processes in situ remains a major challenge even with the most advanced experimental methods. We tackle this challenge by combining multiscale simulations with experimental analysis methods. The combination provides answers to key tribological questions: How do materials and lubricants change under load? How do tribofilms form, and what composition and structure do they have?

• Coupling of tribometry experiments and multiscale modelling for the prediction of friction and wear
• Simulation of tribochemical processes underlying tribofilm formation to complement experimental surface analyses
• Simulated spectroscopy to support experimental measurements in determining the composition of tribological surfaces

Reference Projects

SupraSlide

Supra-sliding bearings for maximum energy efficiency and precision

SupraSlide aims to bring supra-lubrication from the laboratory into industrial applications. This enables the development of simple, cost-effective sliding bearings with extremely low coefficients of friction and energy savings of up to 90%.

Project Profile: SupraSlide

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Chephren

Chemical-Physical Reduction of Friction Energy - Ultra-Smooth and Superlubricating Coatings for Component Applications

Development of high-performance ta-C-based coatings and innovative tribological systems to achieve superlubricity in machine components, with the aim of significantly reducing energy loss due to friction and thereby lowering CO₂ emissions and resource consumption.

Project Profile: Chephren

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Poseidon II

Energy Efficiency Through Extended Service Life of Bearings Under Tribocorrosive Operating Conditions

Development of innovative tribocorrosion-resistant materials and coatings for seal-less rolling and plain bearings in fluid-lubricated applications under extreme conditions (seawater, organic process media, cleaning agents) to increase service life and energy efficiency.

Project Profile: Poseidon II

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Prometheus

High-Performance Carbon Coatings for Friction-Optimized Engine Components

Development of innovative ta-C-based coatings and lubricants for the comprehensive tribological optimization of all critical engine components (valve train, piston rings, cylinder walls, connecting rods) to significantly reduce friction losses in internal combustion engines and thereby cut energy consumption and CO2 emissions by up to 40%.

Project Profile: Prometheus

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LubeTwin

Development of the continuum-physics core of a digital twin for tribological contacts under boundary and mixed lubrication conditions

The ERC-funded LubeTwin project aims to optimize lubrication in machines and technical systems that rely on highly loaded friction contacts. At the heart of the project is the development of a digital twin that models all lubrication regimes - from dry friction to hydrodynamic lubrication. Using advanced molecular dynamics simulations and machine learning, LubeTwin aims to link the atomic processes of friction with macroscopic friction in technical components. This approach is intended to make friction-inducing mechanisms - which are difficult to study experimentally - computationally accessible.

Project Profile: LubeTwin

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PTFELub

Polytetrafluoroethylene Lubrication of Radial Roller Bearings: Controlling Lubricant Transfer Through Cage Design Based on Materials-Specific Requirements

The solid lubricant polytetrafluoroethylene (PTFE) is frequently used in low-load rolling contacts when the use of conventional liquid lubricants is ruled out due to operating conditions such as vacuum or high temperatures. For use in high-load rolling contacts, however, the strength of PTFE is no longer sufficient, and lifetime lubrication is no longer possible. In rolling bearings, a technical solution to compensate for PTFE loss is continuous relubrication, achieved by incorporating PTFE reservoirs into the rolling bearing cage so that lubricant is gradually transferred to the rolling elements. Additionally, the strength of PTFE can be increased by blending it with the high-performance polymer PEEK. As part of the project, the lubrication mechanisms of PTFE were investigated both experimentally (RWTH Aachen) and via atomistic simulations (Fraunhofer IWM), and the feasibility of delivering PTFE to rolling bearings via a transfer film generated between the rolling elements and the cage was demonstrated.

Project Profile: PTFELub

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GraLub

Mechanisms of Graphite Lubrication in Rolling Contacts

Investigation of transfer layer formation and sliding mechanisms of graphite as a solid lubricant in heavily loaded rolling contacts through multiscale experiments and atomistic simulations, with the goal of developing practical concepts for lifetime lubrication of heavily loaded rolling bearings.

Project Profile: GraLub

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CNTLub

Solid-State Lubrication Using Carbon Nanotubes: Fundamental Understanding of Transfer Layer Formation and Sliding Mechanisms Through Atomistics and Experimental Nanoanalytics

Investigation of the lubrication mechanisms of carbon nanotubes (CNTs) under high-load tribological conditions through multiscale analyses ranging from atomistics to macroscopic applications, with the aim of developing fluid-free, high-performance lubrication systems.

Project Profile: CNTLub

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Sylla, S.; Zeradjanin, D.; Jiang, X.; Staedler, T.; Moras, G.; Moseler, M.; Mayrhofer, L., Surface Passivation and Running-In of Hydrogenated Amorphous Carbon in Hydrogen-Containing Environments, ACS applied engineering materials 4/5 (2026) 2301-2318 Link

Garcia Manzano, E. J.; Sauer, F.; Haber, M.; Mukherjee, A.; Falk, K.; Schwitzke, C.; Bauer, H. J.; Moseler, M.; Schulze, V.; Experimental and multiscale simulation analysis of the lubricant penetration in gear skiving, Production Engineering. Research and development, 19/6 (2025) 1373-1394 Link

Reichenbach, T.; Goeldel, S. v.; Peeters, S.; Vokolos, G.; König, F.; Jacobs, G.; Moras, G.; Moseler, M.; Polytetrafluoroethylene (PTFE) Lubrication of Rolling Point Contacts by Double Transfer Films: Relationships between Friction and Lubricant Film Distribution Revealed by Spacer Layer Imaging and Molecular Dynamics, Tribology transactions, 68/5 (2025) pp. 1102-1113  Link

Walter, M.; Mangolini, F.; McClimon, J. B.; Carpick, R. R.; Moseler, M.; Origin of C(1s) binding energy shifts in amorphous carbon materials, Physical review materials, 9/3 (2025) Art. 035601, 10 pp. Link

Holey, H.; Sauer, F.; Ganta, P. B.; Mayrhofer, L.; Dienwiebel, M.; Schulze, V.; Moseler, M.; Multiscale Parametrization Of a Friction Model For Metal Cutting Using Contact Mechanics, Atomistic Simulations, And Experiments, Tribology letters, 72/4 (2024) Art. 113, 19 pp.  Link

MacLucas, T.; Klemenz, A.; Grünewald, P.; Presser, V.; Mayrhofer, L.; Moras, G.; Suarez, S.; Dienwiebel, M.; Mücklich, F.; Moseler, M.; Multiwall carbon nanotubes for solid lubrication of highly loaded contacts, ACS applied nano materials, 6/3 (2023) pp. 1755 – 1769 Link

Morstein, C. E.; Klemenz, A.; Dienwiebel, M.; Moseler, M.; Humidity-dependent lubrication of highly loaded contacts by graphite and a structural transition to turbostratic carbon, Nature Communications, 13 (2022) Art. 5958, 16 pp. Link

Salinas Ruiz, V. R.; Kuwahara, T.; Galipaud, J.; Masenelli-Varlot, K.; Ben Hassine, M.; Héau, C.; Stoll, M.; Mayrhofer, L.; Moras, G.; Martin, J. M.; Moseler, M.; Barros Bouchet, M.-I. de; Interplay of mechanics and chemistry governs wear of diamond-like carbon coatings interacting with ZDDP-additivated lubricants, Nature Communications, 12 (2021) Art. 4550, 15 pp. Link

Long, Y.; Kuwahara, T.; Barros Bouchet, M.-I. de; Ristic, A.; Dörr, N.; Lubracht, T.; Dupuy, L.; Moras, G.; Martin, J. M.; Moseler, M.; In Situ Synthesis of Graphene Nitride Nanolayers on Glycerol-Lubricated Si3N4 for Superlubricity Applications, ACS applied nano materials, 4/3 (2021) pp. 2721-2732 Link

Goeldel, S. v.; Reichenbach, T.; König, F.; Mayrhofer, L.; Moras, G.; Jacobs, G.; Moseler, M.; A combined experimental and atomistic investigation of PTFE double transfer film formation and lubrication in rolling point contacts, Tribology letters, 69/4 (2021) Art. 136, 16 pp. Link

Kuwahara, T.; Romero, P. A.; Makowski, S.; Weihnacht, V.; Moras, G.; Moseler, M.; Mechano-chemical decomposition of organic friction modifiers with multiple reactive centres induces superlubricity of ta-C, Nature Communications, 10 (2019) Art. 151, 11 pp. Link

Walter, M.; Moseler, M.; Ab initio wavelength-dependent raman spectra: Placzek approximation and beyond, Journal of chemical theory and computation: JCTC, 16/1 (2020) pp. 576-586 Link

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