Wear Protection and Advanced Ceramics

We use experimental friction and wear analysis methods to determine friction coefficients and wear rates, including Stribeck curves. We test, assess and numerically simulate the effects of desired and undesired changes in the tribological contacts involved in ceramics, coatings, polymers and metals. We investigate the tribo-chemistry, tribo-corrosion and 'third bodies' associated with the effects of lubricants, media and temperature.

This enables us to identify the conditions under which the materials can be used reliably (sliding speed, contact loads, temperatures, lubrication requirements, smooth running) and what the effects of a material substitution would be. We also carry out damage analyses, and evaluate and optimize the mechanical behavior of ceramic materials and components. This leads to process and component optimizations, e.g. for ceramic tools, ball bearings, roller bearings, slide bearings or pumps. Another focus of research work here is tribo-polymers, liquid crystalline lubricants and graphenes.

What we offer

 

  • Tribological component testing under application-relevant conditions
  • Switchable tribosystems
  • Tribology and tribocorrosion of plain bearings and mechanical seals in corrosive environments
  • Qualification of water-based lubricants
  • Development of tribological test arrangements for corrosive operating conditions and high operating temperatures
  • Numerical simulation of tribocontacts with regard to contact mechanical load, wear and contact fatigue

Topics

 

Tribological coatings


The tribology of ceramic materials and layers depends on the conditions of use. It is essential to replicate the conditions of use to gain an understanding of tribological systems.

Through a combination of application-oriented experiments, differentiated surface analysis and numerical simulation, we develop the optimum solution in consultation with material developers, component manufacturers and users...

 

Ceramic materials and components


Due to their mechanical, thermal and tribological properties, ceramic materials are superior to metallic materials or polymers in many applications. However, it is necessary to keep the component loads in use within defined limits. That is why load limits are determined for temperatures up to 1600° C or in corrosive media. The experimental results are used in numerical simulations to evaluate stress situations. to optimize component geometry, or to ...

 

High temperature tribology


We make abrasion and wear of materials and components calculable: via our experiments in which we examine, in an application oriented way, the thermal effects of materials and their surfaces.
High operating temperatures are ubiquitous: they can be found in drive units, in industrial production processes like hot forming and machining and in energy production.  Just as ubiquitous, however, is the problem that unlubricated contacts have to function as long and as reliably as possible...

 

Diamond ceramics: an appropriate material for underwater systems

 

In order to be able to extract raw materials from the sea economically and in an environmentally friendly manner, the processes must run as smoothly as possible - otherwise the downtime, maintenance and repair of marine systems would result in enormous costs. In cooperation with...

 

Development of water-based lubricants

 

The Fraunhofer IWM solves the corrosion problem of water-based lubricants by establishing an electrochemical field produced by the bearing itself. The new method has been successfully developed and demonstrated on sintered slide bearings. The lubricant itself consists of ...

 

Investigation of electrochemical and tribological interactions

 

By combining different electrochemical methods with tribological tests, we investigate complex electrochemical and electro-tribological interactions. These fundamental investigations provide results that can be used to optimize lubricants and identify innovative additives. Electrochemical potentials cab be utilized to control or program friction in lubricants made from ionic liquids. In order to prevent damage caused by hydrogen embrittlement, we determine the hydrogen permeation as a function of the lubricants, the load spectrum and the material by combining tribology and electrochemistry.

 

Reliability and operational behavior of biomedical materials and implants


Hip joint prostheses, bone cements and dental implants in patients must survive several million load cycles without failure due to fatigue. Bone cement should have no critical creep deformation under load. The mechanical properties of resorbable osteosynthesis plates should change during the removal process in a defined way. A micro bone screw should quickly and definitely “grip” when screwed into ...

 

Reliability in generative manufacturing


Generative production processes are becoming more important in the production of small series, customized components and the manufacture of complex component structures. The transition from rapid prototyping to rapid manufacturing requires that produced parts be subjected to reliable and defined quality control. To do this, we experimentally and computationally define the internal stresses and shape distortions that arise from the layered structure...

 

Polymer Tribology


The tribology of polymers can be complex: a new lubricant can lead to unexpected friction and wear behavior of a plastic gear wheel, in some hinges of a batch the plastic bearings "creak", and an elastomer shows significantly higher wear under tribological load in an aggressive atmosphere. We develop solutions for these issues ...

Wear protection, Advanced Ceramics publications

 

Contributions to scientific journals, books and conferences as well as dissertations and project reports...

© Dirk Mahler/ Fraunhofer IWM
Rheometer with tribo-measurement cells (co. Anton Paar) (picture left to right) Dr. Tobias Amann and Dr. Andreas Kailer.
© Fraunhofer IWM
Logo: Wissenschaftspreis des Stifterverbandes 2014. Forschung im Verbund

Press release: Liquid crystal lubricant (Stifterverband Science prize winner)

 

Thanks to a new lubricant, small gears can run with virtually no friction. Made from liquid crystalline fluid, these lubricants drastically reduce friction and wear. For this, Dr. Andreas Kailer und Dr. Tobias Amann awarded together with their project partners the price »Wissenschaftspreis des Stifterverbandes 2014 - Forschung im Verbund«.

Lubricants are used in motors, axels, ventilators and manufacturing machines. Although lubricants are widely used, there have been almost no fundamental innovations for this product in the last twenty years. Together with a consortium, the Fraunhofer Institute for Mechanics of Materials IWM in Freiburg has developed an entirely new class of substance that could change everything: liquid crystalline lubricant. Its chemical makeup sets it apart; although it is a liquid, the molecules display directional properties like crystals do. When two surfaces move in opposite directions, the liquid crystal molecules between the two surfaces align themselves so that the frictional resistance is extremely low. This enables nearly frictionless sliding. [more]

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