Principles for the tribological evaluation of intrinsic coating properties

Principles for evaluation of the abrasion resistance of thin coatings are discussed. In addition to the most obvious way of measuring the wear resistance of thin films, i.e, from shallow wear scars, two basically different principles can be distinguished to evaluate the wear resistance of a coating independently of the substrate: either the coating and the substrate are worn down together and their wear resistances are separated from the measured composite wear resistance using information on the load distribution between coating and substrate, or first the coating and then the substrate are worn in sequence and the retardation in wear rate caused by the coating is measured. The basic principles of these two techniques are discussed. (C) 1997 Elsevier Science S.A.