An ultrahard carbon film coating many times slicker than Teflon has been developed by Argonne researchers. The new material's coefficient of friction is less than 0.001 when measured in a dry nitrogen atmosphere--20 times lower than the previous record holder molybdenum disulfide. When tested under the same conditions, Teflon's coefficient of friction is around 0.04.
The ultrahard coating provides many benefits:
- Unlike many existing friction-reducing coatings, Argonne's new coating has exceptional wear resistance and durability that reduce material and energy losses.
- Compared with previous methods of producing carbon coating, the new process is quick--it takes only a few hours--and can produce large amounts of the coating.
- The material adheres well to many kinds of substrates, including plastics.
- Near-perfect finished products have a smooth surface, uniform coverage, and good transparency; they do not require secondary machining or grinding.
- The ultrahard coating means longer lifetimes and improved performance in rolling, sliding, and rotating components.
- Extremely slick coatings are ideal for sliding parts and machining of high-precision surfaces.
- The coating offers higher productivity, lower costs, and improved environmental compliance (reduction or elimimination of flammable and hazardous fluids).
While the most promising applications appear to be those that operate in essentially air-free environments, such as bearings for ultrahigh vacuum instruments, certain mechanical seals, and selected cryogenic, space, and aircraft applications, the material's properties in air and on lubricated surfaces also are impressive. It is expected that this new material may likely find applications in automobile and engine parts such as turbocharger rotors, piston rings, gears and bearings, air-conditioning compressors, and fuel injector components, including possible applications in electronic and micro-electromechanical systems.
In a $2.14 million project, Argonne is working with Front Edge Technology, Inc. (Baldwin Park, Calif.); Stirling Motors, Inc. (Ann Arbor, Mich.; and Diesel Technology Company (Wyoming, Mich.) to further develop the near-frictionless coating to increase engine efficiency, extend wear life, and reduce maintenance costs for motor vehicles. Argonne's effort is funded by the Department of Energy's Energy Research, Laboratory Technology Research Program. The technology was developed with funding from the U.S. Department of Energy, Energy Efficiency and Renewable Energy, Office of Transportation Technologies.
In addition to being named an R&D 100 Award winner, the NFC coating was a finalist in the "Emerging Technology" category of the 1998 Discover Magazine Awards.
For more information see Technology Profile (pdf)