Fractals, engineering surfaces and tribology

Fractal geometry, which is based on modern mathematics and which admits fractional dimensions, is introduced in this paper. Examples of fractional dimensions are 2.2618 and 2.4950; these are, of course, inadmissible in Euclidean geometry. Engineering surfaces, viewed from a wide spectrum of scales which range from micro to macro extents, are then discussed as a vital part of tribology. Based on results of recent research including experimental findings, it is concluded that fractal geometry forms an attractive adjunct to Euclidean geometry in the modeling of engineering surfaces. In other terms, a judicious use of a dual-scale description of surfaces would be most powerful in attacking problems in such areas of tribology as boundary lubrication.