Friction diamond-like carbon

Erdemir, A., EryUmaz, O. L., and Fenske, G., Synthesis of Diamond-like Carbon Films with Superlow Friction and Wear Properties,"/. Vac. Sci. Technol. A, Vol. 18, 2000, pp. 1987-1992. 

Voevodin, A. A., Phelps, A. W., Zabinski, J. S., and Donley, M. S., Friction Induced Phase Transformation of Pulsed Laser Deposited Diamond-like Carbon, Diamond Relat. Mater, Vol. 5,1996, pp. 1264-1269. 

Heimberg, J. A., Wahl, K. J., Singer, I. L., and Erdemir, A., "Friction Behavior of Diamond-like Carbon Coatings Time and Speed Effects, Appl. Phys. Lett., Vol. 78, 2001, pp. 2449-2451. 

Choi, J., Ishida, T, Kato, T, and Fujisawa, S., Self-Assembled Monolayer on Diamond-Like Carbon Surface Formation and Friction Measurements, Tribol. Int., Vol. 36, 2003, pp. 285-290. 

Graphite is probably the most widely used lamellar solid lubricant. Unlike M0S2, graphite has a lower friction and lower wear in the presence of moisture than in vacuum. Therefore, graphite is not recommended for vacuum or high-temperature applications. But another form of carbon, amorphous hydrogenated carbon films (also called diamond-like carbon), has the reverse behavior It works extremely well in vacuum, but its friction coefficient is increased by the presence of moisture [37]. 

Agrawal, C.M., Micallef, D.M., Wirth, M.A., Lankford, J., Dearnaley, G. and McCabe, A.R. (1993) The effects of diamond-like-carbon coatings on the friction and wear of enhanced UHMWPE-metal couples. Trans 21st Annual Meet of the Society For Biomaterials, Birmingham, AL. 26, 10. 

Zsidai and co-workers [29] reported results of a series of test carried out to determine the friction properties of engineering plastics by the measurement of small and large test specimens on a steel and diamond-like carbon coating surface. The objective was to compare the friction properties of a surface provided with a diamond-like carbon coating with measurements obtained on a steel surface as a function of the engineering plastic used, and to examine the practical possibilities of the diamond-like coating. The plastics tested included PA, polyacetals and PET/PTFE. 

By using chemical vapour deposition (CVD) technology at a relatively low temperature, Nissin Electric, Kyoto, Japan, claims it is able to apply diamond-like carbon coatings to materials such as plastics and rubber, improving their properties of friction, abrasion resistance and insulation. 

The other article is a recent updated review entitled Tribology of Diamond-like Carbon and Related Materials by Grill [36]. Interfacial chemical changes are held responsible for the friction and wear phenomena of diamond films. These changes involve the formation of nondiamond carbon found by Raman spectroscopy by Pajcini, Vohra, and Gardos and others referred to earlier. 

The work on carbon nitride solids is strongly related to research on diamondlike carbon (DLC) materials [5, 6]. DLC materials are thin film amorphous metastable carbon-based solids, pure or alloyed with hydrogen, which have properties similar to that of crystalline diamond (high hardness, low friction coefficient, high resistance to wear and chemical attack). This resemblance to diamond is due to the DLC structure, which is characterized by a high fraction of highly cross-linked sp -hybridized carbon atoms. To obtain this diamond-like structure... 

PVD coatings provide considerable potential in terms of the sliding behavior. The production of anti-wear and anti-friction coatings through PVD processes has become part of the state of the art. This allows a layer deposition on almost all substrate materials with almost any chemical composition. Metallic layers but also such as carbon, diamond, and diamond-like layers can be produced. The usual layer thicknesses range from 2 to 6 pm, and can be applied at temperatures of 150 to 500 °C. Low alloy steels can be coated without loss of hardness and good adhesion due to the low coating temperatures. 

Most of the solid lubricants mentioned above owe their low-Mction characteristic primarily to a lamellar or layered crystal structure (see two of them in Figure 6.1 as typical examples). When present at a sliding contact interface, these solids shear easily along their atomic shear planes and thus provide low friction. Some of the solid lubricants do not have such layered crystal structures, but in applications, they too provide very low friction and wear. For example, certain soft metals (In, Pb, Ag, Sn, etc.), PTFE, a number of solid oxides and rare earth fluorides, diamond and diamondlike carbons, etc., can also provide fairly good lubrication despite the lack of a layered crystal structure like the ones shown in Figure 6.1 [1]. In fact, diamondlike carbon films are structurally amorphous but provide some of the lowest friction and wear coefficients among all other solid materials available today [8]. 

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