Friction and wear in tribological systems are phenomena that can be interpreted on a macroscopic scale. The emergence of micro and nano-sized systems requires the treatment of tribological phenomena through the concept of fractals. Thus, to perceive the tribological phenomena occurring in a macro-system, it is fundamental to think about them at the micro-scale and nano-scale, that center, for case, on the level of hardness and atomic composition. This article realizes a survey of the main concepts about treating the tribological issues in terms of fractals. It is clear that the continuous change of the micro and nano topography of the friction surfaces during the dynamic functioning of various mechanisms and the tribological processes taking place can be treated using the fractals and chaos theory. To this end, it is concluded that all the existing theories in tribology should be adapted to include fractal dimension and fractal roughness.

Fractals and chaos theory provide means of modeling dynamic changes in micro and nano topography on friction surfaces caused by various tribological mechanisms and processes. Friction and wear phenomena in tribological systems can be interpreted on a macroscopic scale. With the development of miniaturized scale and nanoscale systems, it has been launched the hypothesis that macro-level systems cannot reflect the microscale and nanoscale phenomena. A conclusive case is given by the calculation of frictional torque in microscale orientation, in this situation being found that models created by bearing producers cannot validate experimental results. By applying the “box-counting” method, it is possible to estimate the fractal dimension both directly and indirectly by comparing the area-perimeter-scale relations. Based on scaling equations, a system was created for this operation. The conclusion is that all existing theories in tribology should be adapted to take into account fractal size and fractal roughness.