Tribology definition

Erosion is defined as the loss of hard tissue by chemical means not derived from bacteria, i.e. the dissolution of hard tissue by acid where the acid source is not the oral bacteria [5], Erosion may be caused by either intrinsic (e.g. stomach acid) or extrinsic (e.g. dietary) sources. Erosion is often associated with the consumption of acid products, such as fruits or acid beverages, or with medical conditions where reflux of acidic into the oral cavity is present. Interestingly, the term erosion is widely used in other fields where the definition is rather different. For example, in the field of tribology, erosion refers to the loss of material from a surface by solid or liquid impacts [6], In the classical tribological definitions, the mechanism dentists refer to as erosion would be described as corrosion, or tribo-chemical wear. 

Another important issue associated with tribological simulations involves the definition of the system to be studied. For example, a simple tribological system consists of two atomically flat, defect-free surfaces sliding past one another. Because of computational convenience, it is common... 

The Tribology Book Series is well established as a major and seminal archival source for definitive books on the subject of classical tribology. The scope of the Series has been widened to include other facets of the now-recognised and expanding topic of Interface Engineering. 

ImfeldT Dental erosion. Definition, classification and links. Eur J Oral Sci 1996 104 151-155. Hutchings IM Tribology Friction and Wear of Engineering Materials. London, Edward Arnold, 1992. 

Corrosion (of metals) and fracture (of all materials) each amounts to approximately of the GNP in the U.S., and probably in other industrialized nations. Wear, the other degradative process of capital equipment, has not been discussed as yet. However, from the results presented in Ref. 15 and 16, it can be concluded that the application of tribology could save 1.1 to 1.5 of the GNP in the U.S. in 1971. From the definition used (16) this represents costs somewhere between avoidable costs and total costs, the reference "World being essentially the World IV of the NBS fracture study. While the subject merits further study, the results indicate that the costs of wear are roughly comparable to the costs of corrosion and fracture, but perhaps somewhat less. It can thus be concluded that the overall costs of these three degradative processes amount to somewhat more than 10 of the GNP. Costs associated with the other degradative process mentioned earlier are not known to this author, but clearly will raise this total. 

The element of indeterminateness in this definition is to a certain extent advantageous, as the borderline between surface interactions which can be regarded as tribological and those which cannot is not firmly established. For example, the interaction between two charged surfaces as they approach each other is ordinarily thought of as electrical behavior. However, as we shall find when we come to the examination of contacting... 

He also stated that every fiictional body has a resistance equal to one quarter of its weight. In other words, he suggested a Coulomb coefficient of friction of 0.25 for the bodies. This value is high considering most of the sliding bodies today however, in Leonardo da Vinci s time, the tribological characteristics of the bodies were definitely inferior in comparison to present age. Leonardo da Vinci did not publish his theories on friction and he never got credit for it. 

Mechanochemistry (or Tribochemistry) is usually defined as a science dealing with the chemical and physicochemical changes of substances due to the influence of mechanical energy [23] (see Appendix A for other definitions of mechanochemistry). On the other hand, the term tribology is commonly used to refer to the science of interacting surfaces in relative motion with respect to friction, lubrication, and wear [41]. 

Plastics are frequently used for applications requiring erosion resistance, but there does not seem to be much activity or interest in the tribology community of the 1990s. However, there are a number of tests that are applied and have been used to rate erosion resistance of plastics. Erosion, by definition, is progressive loss of material fiom a solid surface due to mechanical interaction between that surfitce and a fluid, a multicomponent fluid, or impinging liquid or solid particles (3). The field of erosion is usually separated into a number of forms of erosion liquid erosion, either continuous stream or droplet, solid particle erosion, slurry erosion, and cavitation erosion. Each have separate laboratory tests. 

The term "slip" has acquired different meanings. It can mean "solid-like sliding" in the sense of friction and tribology. While such phenomena can definitely be investigated with shear-wave resonators, they are outside the scope of this chapter. Second, slip may denote interfacial shear thinning in complex liquids. The well-known everyday example is toothpaste. When squeezed out of the tube, toothpaste experiences "plug flow" because the large stress at the wall induces structural transformations inside the paste (such as... 

The term tribology (Greek tribein friction) is defined as the science of friction and its consequences. As an introduced generic term, tribology refers to the industrial use and knowledge in the areas of wear, friction, and lubrication. To better understand wear and its causes and effects, a definition should take place first. According to DIN 50320 [1], the following applies ... 

According to this concept, the wear process starts with the detachment of particles from the sliding partners. The detached particles remain for a certain time trapped between the two contacting bodies where they form a separating third body that influences contact stress distribution and thus the overall tribological behaviour. The effective material loss associated with wear is given by the definitive ejection of third body particles from the contact. In case of tribocorrosion, the third body approach should be adapted to include the mass flow associated with corrosion processes. 

ECSS-E-30 defines the mechanical engineering requirements, with Part 3A for mechanisms. The latter contains a mandatory list of requirements applicable to concept definition, design, analysis, development, production, test verification and in-orbit operation of mechanisms to meet mission requirements. The main tribological criteria are contained within sections in the Standard on Design, and on Verification. These will now be considered in more detail. 

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