ABSTRACT
Friction and wear are caused by complicated and multiplex sets of microscopic interactions between surfaces that are in mechanical contact and slide against each other. These interactions are the result of the materials, the geometrical and topographical characteristics of the surfaces, and the overall conditions under which the surfaces are made to slide against each other, e.g., loading, temperature, atmosphere, type of contact, etc. All mechanical, physical, chemical, and geometrical aspects of the surface contact and of the surrounding atmosphere affect the
surface
interactions and thereby also the tribological characteristics of the system. Therefore, friction and wear are not simply materials parameters available in handbooks; they are unique characteristics of the tribological system in which they are measured.
