Introduction to Tribology

Why is Tribology Important

Traditional Applications
Tribology is the study of surfaces moving relative to one another, a phenomenon that affects our lives in a multitude of ways every day. The term tribology is based on the Greek word for rubbing and, although the term itself was not coined until 1964, there are images of tribology in action from as long ago as ancient Egypt, when early tribologists used oil to help facilitate sliding of large statues. Generally, tribology includes three key topics: friction, wear and lubrication. Friction is the resistance to relative motion, wear is the loss of material due to that motion, and lubrication is the use of a fluid (or in some cases a solid) to minimize friction and wear. The field is necessarily interdisciplinary and utilizes skills from mechanical engineering, materials science and engineering, chemistry and chemical engineering and more. Tribology is both technologically relevant and scientifically fascinating, and it’s definitely an exciting time to be a tribologist! Click here to learn more about traditional applications of tribology.

Everyday Examples of Tribology

In addition to the more traditional applications of tribology, there are many products and processes we use on a daily basis that rely on the principles of tribology, for example, products and processes in healthcare, sports and nature. In some cases we want to maximise the friction (such as on the soles of our shoes) and in others we want to minimize friction (such as on the bottom of a bobsled). Click here to learn more applications of tribology in your everyday life.
Role of Tribology in Energy Efficiency
Significant energy is lost due to friction in sliding interfaces. By finding ways to minimise friction and wear through new technologies in tribology, a greener and more sustainable world is possible. Click here to learn more about energy waste due to friction and wear.


Tribology 101

Tribology is an interdisciplinary field that includes mechanical engineering; materials science and engineering; chemistry and chemical engineering; and more. The magnitude of this resistance is a function of the materials, geometries, surface features and operating environment. There are also many different areas of focus within tribology. Generally speaking, there are three major topics within tribology: friction, wear and lubrication. Each of these is described in more detail below.

Friction
Friction is, by definition, the resistance to motion. The magnitude of this resistance is a function of the materials, geometries and surface features of the bodies in contact, as well as the operating conditions and environment. It is often desirable to minimize friction to maximize the efficiency of a component or process. Generally speaking, friction increases with load and surface roughness and can be decreased by the use of a lubricant. 
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Wear
Wear is the loss of materials, usually due to sliding. Typically wear is undesirable as it can lead to increased friction and ultimately to component failure. Like friction, wear is typically minimized by using a lubricant to separate the two bodies so that they do not directly touch one another. 
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Lubricants and Lubrication

Lubricants are primarily used to separate two sliding surfaces to minimize friction and wear. They also perform other functions, such as carrying heat and contaminants away from the interface. Lubricants are often liquids, typically consisting of oil and added chemicals, called additives, which help the oils better perform specific functions. However, there are some applications where lubricants can be gases or even solids. 
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Other Topics in Tribology

There are several topics that are integrally related to the core areas of friction, wear and lubrication, but that deserve their own description. These are surface roughness, contact mechanics and nanotribology. Each topic will be briefly introduced here. 
Click here to learn more about other tribology topics.