Tribology
Tribology (friction theory, from ancient Greek τρίβειν tribein , German 'rub, wear' and λόγος lógos , here: 'doctrine' ) deals with the scientific description of friction , the calculation and measurement of coefficients of friction , wear and the necessary lubrication between interacting surfaces that are in relative motion. This also includes the development of technologies for the optimization of friction processes, which can be described as “interacting surfaces in relative motion” or “tribological system”. Tribology is interdisciplinary in materials science , physics , chemistry and mechanical engineering .
tasks
Tribology examines friction, lubrication and wear of bearings , guides , gears , motors and other machine elements . In addition to the development of suitable lubricants, questions of material selection, surface treatment and coating and surface topography are in the foreground of current developments. In addition to questions in mechanical engineering, there are numerous other areas in which friction and wear are of great importance. For example, biotribology is concerned with improving endoprostheses or geotribology with faults .
Organizations dealing with tribology are the non-profit association Gesellschaft für Tribologie (international conference on friction, lubrication and wear ) in Germany, the Austrian Tribological Society in Austria and Swiss Tribology in Switzerland . There are also institutes with a tribological focus at the universities in Aachen , Berlin , Clausthal , Hanover , Magdeburg and Munich .
relevance
A research report from 1966 put the costs caused by friction and wear in the UK at 1.1–1.4% of gross domestic product . This resulted in increased public awareness of the term tribology and increased funding for projects and associations related to tribology.
In 2017, a study on the influence of tribology on global energy consumption , costs and emissions was published. The study takes into account energy consumption in transport , manufacturing , energy generation and construction . The following could be determined:
- 23% of global energy consumption is caused by tribological contacts. 20% result from friction and 3% from the reconditioning of worn components.
- By using new technologies to reduce friction and protect against wear, energy losses due to friction and wear could be reduced by 40% in the long term (15 years) and by 18% in the short term (8 years). In the short term, this would lead to annual gross domestic product savings of 1.4%. 8.7% could be saved in the long term.
- The greatest short-term energy savings can be made in transportation (25%) and power generation (20%). The potential savings in construction are estimated at 10%.
- The use of advanced tribological technologies can reduce global carbon dioxide emissions by up to 1,460 million tons of carbon dioxide equivalent. In the long term, 3,140 million tonnes of carbon dioxide equivalent could be saved. This could save 450,000 million euros in the short term and 970,000 million euros in the long term.
The increasing demand for energy saving has recently led to increased research on superlubricity . In addition, the development of new materials such as graphenes and ionic liquids allow fundamentally new approaches to solving tribological problems.
Concept and classification
The term was used as a technical term in England from around 1966:
- According to Peter Jost (1966): "Tribology is the science and technology of the interacting surfaces that are in relative motion and the related practical processes."
- According to DIN 50323 (standard has been withdrawn): “Tribology is the science and technology of surfaces that interact with one another in relative motion. It covers the entire area of friction and wear , including lubrication , and includes corresponding interfacial interactions both between solids and between solids and liquids or gases. "
- According to Horst Czichos (1992): "Tribology is an interdisciplinary field for the optimization of mechanical technologies by reducing the energy and material losses caused by friction and wear."
Under Nanotribology the study of friction is in the nanometer range understood. Either special friction effects in micro- or nanotechnology ( atomic force microscopes , hard disk heads , etc.) or the investigation of friction itself at the atomic level are the subject of research.
The Tribophysik is that part of tribology, a body to be examined in the structural changes of the surface, acting on the mechanical energy. The tribochemistry deals with the induced by the action of chemical changes.
The contact mechanism is involved in the calculation of bodies that are in static or dynamic contact. Related disciplines are also surface chemistry and surface physics .
Important personalities
- Leonardo da Vinci investigated the static friction coefficient on the inclined plane and is considered the founder of modern tribology.
- Sir Isaac Newton laid the foundations of viscosity and developed the concept of Newtonian fluids .
- Guillaume Amontons investigated static friction and rediscovered the laws of sliding friction ( Amonton's laws ): The frictional force is proportional to the normal force and independent of the apparent contact area; da Vinci knew about these laws about 200 years earlier.
- Charles Augustin de Coulomb suggested that the frictional resistance of a rolling wheel or cylinder is proportional to the load and inversely proportional to the radius of the wheel. Material conformities were neglected in the description.
- Osborne Reynolds contributed significantly to the lubricating film theory .
- Richard Stribeck discovered the Stribeck curve named after him , which describes the coefficient of friction in lubricated bearings.
- In 1950, Frank Philip Bowden and David Tabor wrote the first “modern” book on tribology.
literature
- Wilfried Bartz u. a .: Introduction to tribology and lubrication technology. expert publisher, 2010, ISBN 978-3-8169-2830-0 .
- Wilfried Bartz u. a .: expert Practice Lexicon Tribology PLUS - 2010 Terms for studies and work. expert verlag, 2000, ISBN 978-3-8169-0691-9 .
- Tabor, Bowden: Friction and Lubrication of Solids. Clarendon Press, Oxford 1950.
- Tabor, Bowden: Friction and Lubrication of Solid Bodies. Springer-Verlag, Berlin 1959.
- Heinrich Hertz : About the touch of solid elastic bodies (1881) (PDF file; 1.81 MB)
- Dieter Klamann: Lubricants and related products. Verlag Chemie, Weinheim 1982, ISBN 3-527-25966-X .
- Theo Mang, Wilfried Dresel: Lubricants and Lubrication. Wiley-VCH, Weinheim 2001, ISBN 3-527-29536-4 .
- Uwe J. Möller, Udo Boor: Lubricants in operation. VDI-Verlag, Düsseldorf 1999, ISBN 3-540-62114-8 .
- Bo NJ Persson: Sliding Friction. Physical Principles and Applications. Springer, 2002, ISBN 3-540-67192-7 . (In this book many frictional instabilities in lubricated and dry friction pairs are examined).
- Oltwig Pigors: Materials in tribotechnology - friction, lubrication and wear resistance of materials and components. German publishing house for basic industry, Leipzig / Stuttgart 1993.
- Valentin L. Popov: Contact Mechanics and Friction. A text and application book from nanotribology to numerical simulation. Springer-Verlag, Berlin 2009, ISBN 978-3-540-88836-9 .
- Ernest Rabinowicz: Friction and Wear of Materials. Wiley-Interscience, 1995, ISBN 0-47-183084-4 .
- Werner Stehr, Klaus Dobler: The bratwurst and the bearing damage - tribology to be amazed, touch and experiment. 3rd edition, Dr. Tillwich GmbH, 2008, ISBN 978-3-00-019479-5 .
- Tribology and lubrication technology
Web links
- GfT worksheet 7- Tribology, wear, friction
- GfT Society for Tribology eV
- Competence center tribology at the University of Mannheim
- Video: Tribology - Friction, Wear, Lubrication . Institute for Scientific Film (IWF) 1986, made available by the Technical Information Library (TIB), doi : 10.3203 / IWF / C-1619 .
Individual evidence
- ^ Jost, Peter: Lubrication (Tribology) - A report on the present position and industry's needs . Ed .: Department of Education and Science. HM Stationery Office, London, UK.
- ↑ Kenneth Holmberg, Ali Erdemir: Influence of tribology on global energy consumption, costs and emissions . In: Friction . tape 5 , no. 3 , ISSN 2223-7690 , p. 263–284 , doi : 10.1007 / s40544-017-0183-5 ( springer.com [accessed November 12, 2019]).
- ^ Ali Erdemir, Jean-Michel Martin: Superlubricity . Elsevier, 2007, ISBN 978-0-08-052530-3 ( google.de [accessed November 12, 2019]).
- ^ Diana Berman, Ali Erdemir, Anirudha V. Sumant: Graphene: a new emerging lubricant . In: Materials Today . tape 17 , no. 1 , January 1, 2014, ISSN 1369-7021 , p. 31–42 , doi : 10.1016 / j.mattod.2013.12.003 ( sciencedirect.com [accessed November 12, 2019]).
- ↑ Ichiro Minami: Ionic Liquids in Tribology . In: Molecules . tape 14 , no. 6 , 2006, p. 2286–2305 , doi : 10.3390 / molecules14062286 ( mdpi.com [accessed November 12, 2019]).
- ↑ GfT worksheet 7 ( Memento of the original from August 19, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Horst Czichos, Karl-Heinz Habig: Tribology Handbook. Vieweg-Verlag, 1992, ISBN 3528063548 .