In mechanical systems components are in contact transmitting a force from one component to another either stationary or under relative motion. The components may be lubricated and operate in a specific environment. Fundamental research of the Surface Technology and Tribology section focusses on the interaction between surfaces and the related engineering practices. Research and education of the Surface Technology and Tribology section are related to:
- High Tech Systems and Energy, chair: Surface Technology and Tribology,
- Health, chair: Skin Tribology and
- Reliability and Durability, chair: Tribology-based Maintenance.
The subject high tech systems deals with contacts in mechanical systems operating in extreme environments, i.e. low temperature, high temperature as well as low pressure (e.g. vacuum systems) and high pressure environments (i.e. deep sea mining). Although these contacts may appear very different, there are many similarities. In order to realize such contacts, ceramics, polymers, dedicated coatings and surface treatments are required instead of metallic surfaces lubricated with (mineral) lubricants. If contacts are lubricated, typically solid lubricants are used. The research is performed by a combination of modelling and experiments in these extreme environments. The subject energy is a big societal theme which gets a lot of attention nowadays to produce energy in a sustainable way. Efficient use of the available energy is of importance. Therefore attention is paid to reduce frictional losses and waste of components, which results in less loss of materials and energy to make these components.
Product development and engineering technology for health care, sports and medical applications rely on innovation in simulation and visualization techniques that can predict e.g. the human perception of products as a function of design optimization parameters. Understanding the interaction of human skin and product surfaces requires a thorough knowledge of the tribological phenomena occurring at the interface between the human skin and the product surface. Within this theme, research on contact models is conducted focusing on the viscoelastic response of human tissue, on tissue deformation at the scale of mechanoreceptors, and focusing on the thermal aspects. Understanding and predicting friction is as important as creating the tools to influence friction. Friction control is required for constant performance of medical tools like catheters, endoscopes and cytoscopes that interact with human tissue. Human tissue tribology requires in vivo, subject and anatomical location specific test methods. Such tools are developed within ongoing research projects.
The subjects that are addressed in Tribology Based Maintenance are durability and reliability. The developed knowledge should lead to the prediction and/or extension of maintenance intervals of systems with respect to friction and wear. Regarding this subject a system has two dominant lines of defense against failure: Protection by a very thin lubricant film or by tribo generated layers. On the basis of this hypothesis research is directed towards the development of models for wear and lubrication. Physical models make it possible to predict the performance under conditions which cannot be tested, either because of unacceptable high costs, or because of unacceptable duration. Regarding research two main lines of research can be recognized: I) research focusing on the capability of the lubricant to form a protective lubricant film, which separates the surfaces and the degradation of this ability during operation, II) the ability of solid layers formed by the system to prevent failure and minimize wear.
Applications are for instance (however not limited to) wheel rail contact, camshaft follower contacts, rolling bearings and plain bearings. The wear models combine the response of the material and lubricant on severe operating conditions.