Design of low-friction PVD coating systems with enhanced running-in performance - carbon overcoats on TaC/aC coatings
2012 (English)In: Nordtrib 2012, 15th Nordic Symposium on Tribology: Final papers, 2012Conference paper, Abstract (Refereed)
The widespread use of low friction PVD coatings on machine elements is limited by the high costs associated with fulfilling the demands on the surface quality of both the supporting substrate and the counter surface. In this work, an attempt is made at lowering these demands, by adding a sacrificial carbon overcoat to a TaC/aC low friction coating. Both coatings were deposited by planar magnetron DC sputtering, as separate steps in a single PVD-process. Coatings were deposited on substrates of two different surface roughnesses, in order to test the ability of this coating system to function on rougher substrates. Reciprocating ball on disc tests were performed, using balls with two different surface roughnesses. The worn surfaces were investigated using 3-D profilometry and SEM. The ability of the different overcoats to initially reduce the roughness of both the coated surface and the counter surface and to produce stable, low-friction conditions was examined for the different initial roughnesses. The implications for design of efficient run-in coatings for various systems are discussed.
Place, publisher, year, edition, pages
Low friction coatings, surface roughness, running in, PVD DLC
Research subject Engineering Science with specialization in Tribo Materials; Engineering Science with specialization in Materials Science
IdentifiersURN: urn:nbn:se:uu:diva-181805OAI: oai:DiVA.org:uu-181805DiVA: diva2:559585
Nordtrib 2012, 15th Nordic Symposium on Tribology, 12-15 June 2012, Trondheim, Norway