- Related Topics:
- physics
- lubrication
- wear
- friction
tribology
-
What is tribology?
Tribology is the study of interacting surfaces in relative motion, encompassing friction, wear, and lubrication. It is an interdisciplinary field drawing from physics, mechanical engineering, material science, and chemistry.
Tribology addresses fundamental phenomena encountered daily, with beneficial applications that enable modern life. However, it also presents challenges due to energy wasted by friction and the need to replace worn objects. Examples of tribological applications include ceramics used in industrial processes, manufacturing, and even household items like faucet valves and wear-resistant spikes for sport shoes.
3 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What are friction and wear in tribology?
In tribology, friction is the resistance to sliding between contacting bodies and is vital for many mechanisms. It depends on surface adhesion and irregularities, with the friction amount nearly independent of contact area but proportional to the load pressing the surfaces together.
Wear is the removal of material from a solid surface due to mechanical action by another solid, a universal phenomenon in sliding or touching bodies. There are four basic types of wear: adhesive, abrasive, corrosive, and surface-fatigue. Lubricants are often used to diminish friction and wear between sliding surfaces.
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
Why is lubrication important in tribology?
Lubrication is a critical aspect of tribology, the study of interacting surfaces in relative motion. The use of lubricants reduces friction between surfaces, with the friction between two lubricated surfaces potentially being 200 times less than that of non-lubricated surfaces. Primarily, lubricants manage friction and wear, but they also offer other advantages that depend on the application. Proper lubrication combats wear caused by abrasion, corrosion, and solid-to-solid contact. Lubricants achieve this by creating a film that increases the separation between sliding surfaces, which reduces damage from abrasive contaminants and surface asperities.
2 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
How do engineers use tribology to improve machines?
Tribology, the study of interacting surfaces in relative motion, helps engineers improve machines by focusing on friction, wear, and lubrication.
- Reducing Wear By understanding wear processes, engineers can select appropriate materials like tribological ceramics for machine parts to extend their lifespan.
- Improving Lubrication Tribology aids in designing effective lubrication systems that minimize friction and wear, crucial for continuously moving parts like engines.
- Optimizing Friction Engineers can design systems requiring high friction, like brakes, or low friction, like engine components, by understanding and controlling friction.
- Using Advanced Materials Tribological ceramics are utilized in various applications due to their resistance to wear, such as in mineral processing plants, manufacturing processes, and even household items like ceramic faucet valves.
2 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What everyday examples show tribology in action?
Tribology, the study of interacting surfaces in relative motion, is evident all around us. Friction, wear, and lubrication are its key components.
Everyday examples include:
* Walking, where friction between shoes and the ground is essential
* Nuts and bolts relying on high friction to stay in place
* Engine parts requiring lubrication to minimize friction and wear
* Pencils wearing down as they slide across paper
* Hinges benefit from lubrication to reduce friction.
* Air hockey tables use air as a lubricant to minimize friction.These examples highlight how tribology impacts daily life, from enabling movement to ensuring the longevity and efficiency of mechanical systems.
2 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
tribology, the study of the interaction of sliding surfaces. It includes three subjects: friction, wear, and lubrication (qq.v.). There is a difficulty in that friction is generally characterized as a branch of physics or mechanical engineering, wear is part of the material science of metallurgy, while lubrication is a branch of chemistry. Tribology is thus a complex interdisciplinary subject.
The phenomena considered in tribology are among the most fundamental and most common of those encountered by humans in interaction with their largely solid environment. Many manifestations of tribology are beneficial and, indeed, make modern life possible. Many other effects of tribology, however, constitute serious nuisances, and careful design is necessary to overcome the inconvenience arising from excessive friction or wear. On an overall basis, friction uses up, or wastes, a substantial amount of the energy generated by mankind, while a large amount of productive capacity is devoted to replacing objects made useless by wear.
Friction is the resistance to sliding of a solid when the resistance is produced by a contacting body. It is therefore a vital factor in the operation of most mechanisms. High friction is needed for the satisfactory functioning of nuts and bolts, paper clips, and tongs, as well as in the familiar processes of walking, gripping objects manually, and building piles of sand or of apples. Low friction, however, is desired in objects that are designed to move continuously, like engines, skis, and the internal mechanism of watches. Constant friction is required in brakes and clutches, as otherwise unpleasant jerky movement would be produced.
" height="20" alt="HEW Logo">
Friction has been studied as a branch of mechanics for many hundreds of years and its laws, as well as satisfactory methods of estimating the magnitude of friction, have been known for nearly two centuries. The mechanism of friction, namely, the exact process by which energy is lost as two surfaces slip past each other, is understood only in an incomplete way.
Wear is the removal of material from a solid surface as a result of the mechanical action exerted by another solid. It is such a universal phenomenon that rarely do two solid bodies slide over each other or even touch each other without measurable material transfer or material loss. Thus, coins become worn as a result of continued contact with human fingers; pencils become worn after sliding over paper; and rails become worn as a result of the continued rolling of train wheels over them. Only living things (e.g., bone joints) are in general immune to the permanent damage caused by wear because only they have the property of healing through regrowth. And even a few living things do not heal themselves (e.g., teeth in humans).
The systematic study of wear has been severely hampered by two factors: first, the existence of a number of separate wear processes, which has led to much confusion, especially in terminology; second, the difficulties caused by the small amounts of material involved in wear processes. These difficulties were greatly alleviated when radioactive isotopes of the common engineering metals (iron, copper, chromium, etc.) became available in the 1940s; tracer techniques using these radioisotopes permit measurements of wear, even in small amounts, while it is occurring. This has made it possible to identify types of wear and discover the laws of wear.
The use of lubricants, namely, substances introduced into the interface between sliding surfaces to diminish friction, is an ancient practice, and Egyptian pictures dating back 4,000 years show the application of lubricants to reduce the friction involved in dragging heavy monuments. In modern lubrication practice, the main concern is to reduce the wear that accompanies sliding and, at the same time, to design lubrication systems that will operate for long periods without inspection or maintenance.
The trusted destination for professionals, college students, and lifelong learners.
SUBSCRIBE
A large number of different lubricants are in use at any one time, (a single major oil company may market many hundreds of different varieties), and no aspect of tribology receives as much attention as the development and testing of improved lubricants.