5. Tribology

The main subjects of this chapter are the tribotechnical system, friction, wear and lubrication. Regarding the tribotechnical system essential information on structure, real contact geometry, tribological loads, operating and loss variables are provided. Concerning friction the different friction types, states and mechanisms are discussed. In the sections on wear a lot of details on types and mechanisms of wear, wear profiles and the determination of wear and the average useful life are introduced. The sections on lubrication contain relevant expositions on the lubrication states, like hydrodynamic, elastohydrodynamic, hydrostatic, mixed and boundary lubrication and lubrication with solid lubricants, on the lubricants, like mineral, synthetic and biodegradable oils and additives, lubricating greases and solid lubricants, and on the properties of lubricants, like the behaviour of the oil viscosity depending on temperature, pressure and shear rate and the consistency of lubricating greases.