TRIBOLOGY OF METAL-CONTAINING DIAMOND-LIKE CARBON COATINGS

Ball-on-disk tests were run for several commercial and in-house metal- containing diamond-like carbon (Me:DLC) coatings on steel coupons. The balls, which were made from either WC-Co or 52100 steel, developed no rmal stresses between roughly 100 MPa and 1 GPa during the course of t he experiments. The wear resistance of the Me:DLC coatings from the va rious sources (running against WC balls) differed by up to nearly an o rder of magnitude, but in each case the wear coefficient was constant until the coating wore away. Abrasiveness of the Me:DLC coatings (runn ing against steel balls) differed by up to almost three orders of magn itude. The rates at which the steel wore away fell drastically for som e Me:DLC coatings during the course of the tests. Some possible explan ations for this fall are considered. Coating morphology did not correl ate with any other measured properties. (C) 1997 Elsevier Science S.A.