Diamond-like coating

Bonetti, R. S., and Tobler, M., Amorphous Diamond-Like Coatings on an Industrial Scale, report of Bemex, Olten, Switzerland (1989)... 

Dimigen, H. and Klages, C. R, Microstructure and Wear Behavior of Metal-containing Diamond-like Coatings, Surf. Coat. Technol, Vol. A9,1991,pp. 543-547. 

C-N thin films could be an attractive diamond-like coating material for thermal management in multi-chip modules and micro-scale devices [35]. The field-emission properties of C-N thin films were studied, and indicated an enhancement in the emitted current density [36]. It has been predicted that this material would, as a consequence, have a wide range of potential applications, such as in electronic packaging and wear protective coatings for magnetic storage devices [37]. 

There are deposition techniques by which diamond like coatings can be deposited at... 

Diamond like coatings are basically amorphous and therefore smooth whereas diamond coatings are polycrystalline and hence rough. As a result, the diamond like coating experiences lower sliding friction in wear resistance applications and tends to provide better protection than a diamond coating inspite of the comparatively lower hardness. 

Because the ion-assisted processes enable deposition at temperatures less than 100°C, deposition of diamond like coatings has been attempted on a wide range of substrates, e.g., stainless steel, Copper, ceramics,optical materials (plastics, polymers and polycarbonates),glasses,quartz, sapphire,infrared-transmitting optical materials such as germanium, zinc sulfide and zinc selenide, and a variety of electronic grade materials. Although thin films can be produced... 

Jarrat, M. Stallard, J. Renevier, N.M. Teer, D.G. An improved diamond-like coating with exceptional wear properties. Diamond Relat Mater. 2003, 12, 1003-1007. 

Two types of coatings were tested in this work 50-micron thick soft elastomer coatings used on ink-jet ctirtridges and few-nanometer thin hard diamond-like coatings used on hard magnetic disks. These two types have been chosen as being very different in both hardness and thickness thus covering a wide spectrum of practical applications. 

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. 

Surface properties (such as sliding friction, abrasion resistance and insulation) are claimed to be equal to, or better than, fluorine-treated surfaces and can be achieved at lower cost. In addition, the coated surfaces have good long-term reliability. Nissin also reports that it has developed a flexible diamond-like coating, which can be stretched up to 300%. 

Organic coatings such as nylon are not suitable candidates as alternatives to chromium, since, although they provide excellent resistance to salt fog exposure, water, and other chemicals, they are usually not very hard, and so they perform poorly in wear and erosion tests. Diamond-like coatings (DLC) also have been proposed as an alternative to chromium, since they show to be inert with respect to chemical attack [24]. 

Amorphous diamond-like coatings (DLC), whose primary use is as hard coatings, possess some of the lowe.st friction coefficients ever measured in a wide range of environments from high vacuum to ambient air and dry air 40. For the last 15 years, a great deal of work has been devoted to triboinvestiga-tions of DLC coatings synthesized by physical and chemical vapor deposition proces.ses (PVD, CVD), with a considerable spread in the friction and wear results. This may be explained by the diversity of structures and compositions. 

Diamond is the hardest naturally occurring material. Industrial diamonds are used as abrasives for grinding and polishing diamonds. Diamond and diamond-like coatings prepared using chemical vapor deposition processes are used to make abrasion-resistant coatings for many different applications (e.g., cutting tools). They are, of course, also used in jewelry. 

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