DLC coatings

DLC coatings are already in production in several areas (optical and IR windows) and appear particularly well-suited for abrasion and wear applications due to their high hardness and low coefficient of friction. They have an extremely smooth surface and can be deposited with little restriction of geometry and size (as opposed to CVD diamond). These are important advantages and DLC coatings will compete actively with existing hard coatings, such as titanium carbide, titanium nitride, and other thin film... 

Kajdas, C., and Bhushan, B., Mechanism of Interaction and Degradation of PFPEs with a DLC Coating in Thin-Film Magnetic Rigid Disks A Critical Review," /. Info. Storage Proc. Syst.,Vol. 1,1999, pp. 303-320. 

Ultra-thin DLC Coatings in Magnetic Disk Driver... 

Kimock, F. M. and Knapp, B. J., Commercial Applications of Ion Beam Deposited Diamond-like Carbon (DLC) Coatings," Surf. Coat. Technol, Vol. 56,1993,pp. 273-279. 

Figure 3 shows the friction coefficient as a function of sliding time for 2 N load in either ambient air or 10-torr H.for the DLC coating. The Argonne coating was deposited on top of a Cr bond layer, using plasma-enhanced chemical-vapor deposition with 25% CH4/ 75% H, feed gases at room temperature, to a film thickness of 1-2 pm. H content is expected to be approximately 39 at.% with a hardness of about 14,000 Hv. 

Figure 3. Friction coefficients as a function of sliding time for DLC-coated X-750/M-50...

Fig. 17 Optical micrographs of Ball-on-Disk wear tested (a) uncoated float glass and (b) 30 nm DLC coated float glass.

Fig. 18 Percent haze vs. number of test cycles for Taber tested uncoated polycarbonate and DLC-coated polycarbonate substrates.

There are various applications of DLC in the electronics industry too. For example, DLC coating has been demonstrated to lead to an increase in the electron emission of molybdenum emitters. 

Fig. 20 IR transmission of DLC-coated ZnSe. The approximate transmission of uncoated ZnSe (70%) is aiso pesented for reference.

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