Structure of friction products and the surface of tribological system elements

In the course of wear processes caused by friction of tribological system elements some structural changes in superficial layers of co-working bodies arise, modifying their physical properties. The problem of resistance to abrasive wear is of great importance in technique and, therefore, novel methods are searched in order to reduce tribological wear [12]. In the last years it was found [6, 12] that temperature is a very important factor for friction processes in a tribological system and a significant increase of wear resistance can be reached when a constant, well-chosen temperature is provided in the friction zone. The reduction of wear is accompanied by transfer of the material between surfaces of rubbing bodies and stabilization of coefficient of friction [15]. This phenomenon seems to be very important for decrease of friction losses in tribological systems, although it is not well understood up to now. Mossbauer investigations of the surface layer of rubbing elements and friction products can be helpful for identification of processes that occur in the course of friction as well as comparison of the results obtained under optimal, (i.e. reducing the wear) and non-optimal conditions.