Friction-induced structural transformations of DLC coatings under different atmospheres [electronic resource].
- Washington, D.C. : United States. Dept. of Energy, 2002.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Physical Description:
- 22 pages : digital, PDF file
- Additional Creators:
- Argonne National Laboratory
United States. Department of Energy
United States. Department of Energy. Office of Scientific and Technical Information
- The structural transformations that occur in diamondlike carbon coatings with increasing hydrogen content have been investigated by Raman spectroscopy, transmission electron microscopy, electron diffraction, and electron-energy-loss spectroscopy. Friction tests were performed with uncoated steel balls against coated substrates at contact stresses of 1 GPa in ambient air (relative humidity = 30 - 40%), dry air (relative humidity < 1%), and dry nitrogen (< 1%). The lowest friction coefficient (f < 0.02) was obtained for the most hydrogenated sample in dry nitrogen, where the formation of a third-body layer was observed on the steel surface. Raman spectra obtained from the counterfaces after sliding in humid and dry air revealed a remarkable increase and narrowing of the ''D'' and ''G'' peaks with decreasing humidity. Analysis of peak positions and I(D)/I(G) ratios pointed to an increasing order and an enlargement of the sp² clusters under friction. The shape and position of the carbon K-edge spectra for the transfer layer are affected the same way, although evidence of extended graphite layer formation was not observed. Development of these differing trends was correlated with the hydrogen-to-carbon ratio of the gas precursor used during the synthesis and with the type of surrounding atmosphere.
- Published through SciTech Connect.
International Conference on Metallurgical Coatings and Thin Films(ICMCTF 2002), San Diego, CA (US), 04/21/2002--04/26/2002.
Erdemir, A.; Donnet, C.; Sanchez-Lopez, J. C.; Rojas, T. C.
- Funding Information:
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