Evaluation of new multilayered physical vapour deposition coatings in sliding contact

Much of the current development in surface engineering is focused on multil ayered coatings, i.e., layered combinations of two or more materials, often metals, nitrides or carbides. This concept has proven to offer both a high hardness and an improved toughness as compared to single layer coatings. C onsequently, multilayered coatings has the potential to improve the tribolo gical properties of tools and components. Friction and wear properties of f our new hard physical vapour deposition (PVD) multilayer coatings (TiN/CrN, TiN/MoN, TiN/NbN, and TiN/TaN) were studied using a ball-on-disc tester. A single-layer TiN coating was included as a reference. Three tests with dif ferent counter materials were performed. The overall best performance was f ound for TiN/NbN when tested against a steel ball and TiN/MoN proved to be superior against an alumina ball. Finally, as the coatings were tested in a self-mated contact against a coated ball, TiN/NbN and TiN proved to yield the best combination of low friction and low wear. (C) 1999 Elsevier Scienc e S.A. All rights reserved.