Dissociative Extraction of DLC Boundary Films from Lubricating Oils at Sliding Contact Interfaces by Catalytically Active Nanocomposite Coatings
Nanocomposite coatings hold great promise for enhancing performance, efficiency, and durability of many types of rolling, rotating, and sliding engine parts and components mainly because of their impressive mechanical and tribological properties. In this presentation, we discuss the details of some novel nanocomposite coatings that are capable of extracting diamondlike carbon (DLC) boundary films from lubricating oils at sliding contact interfaces. Specifically, in these coatings, we identified and strategically combined catalytically active hard (nitrides, carbides, or oxides of Mo, W, V, Re, etc.) and soft phases (such as Ag, Ni, Pd, Au, Cu, etc.) in one coating at some optimum concentrations.
When tested under severe contact conditions, these designer coatings were able to dissociate long-chain hydrocarbon molecules of lubricating oils into shorter, dimers and trimers and then deposit them on sliding surfaces as lubricious and highly protective DLC boundary films. Using UV Raman and TOF-SIMS, we have elucidated the structural chemistry of these boundary films and confirmed that they were indeed similar to that of conventional DLC films that are deposited using plasma-based CVD and PVD processes. Under severe sliding, reciprocating, and scuffing test conditions, these DLC boundary films were able to reduce friction by more than 50% and provide extreme resistance to wear and scuffing.
Ali Erdemir is a Distinguished Fellow and a Senior Scientist at Argonne with international recognition and significant accomplishments in the fields of materials science, surface engineering, and tribology. He received his M.S. and Ph.D. degrees in Materials Science and Engineering from the Georgia Institute of Technology in 1982 and 1986, respectively, and his B.S. from Istanbul Technical University in 1977.
In recognition of his pioneering research, Dr. Erdemir has received numerous awards and honors, including the University of Chicago's Medal of Distinguished Performance, five R&D-100 Awards, two Al Sonntag and an Edmond E. Bisson Awards from the Society of Tribologists and Lubrication Engineers, and an Innovative Research Award from the Tribology Division of ASME. He is a Fellow ASME, AVS, ASM-International, and STLE.