Diamondlike Carbon
Diamond-like carbon can be coated on a variety of substrates including metals e.g. steel , polymers e.g. teflon , and ceramics e.g. glass . The coating provides certain diamond attributes, such as high wear resistance, low frictional coefficient, and extreme chemical inertness. There are different methods that may produce DLC, each with specific characteristics. Figure 10.1 shows the classification of DLC types based on the diamond-like bonding sp3 and graphitic bonding sp2 for carbon atoms,...
Fluorinated DLC for Tribological Applications
Diamond-like carbon DLC can be slippery with a frictional coefficient on par with Teflon e.g. 0.1 . Hydrogen terminated DLC may be more slippery than pure carbon DLC, but fluorinated DLC can be super slippery with frictional coefficient less than engine oil 0.01 . The fluorinated diamond is actually superhard Teflon that may be named dialon. Dialon is not only virtually frictionless, it is also super hydrophobic, more so than even lotus leaves. In fact, if dialon is coated onto heart valves, it...
References
1. L. Tang, C. Tsai, W. W. Gerberich, L. Kruckeberg, and D. R. Kania, Biocompatibility of chemical-vapour-deposited diamond, Biomater, 16, 483-488 1995 . 2. A. F. Azevedo, E. J. Corat, N. G. Ferreira, and V. J. Trava-Airoldi, Wettability and corrosion tests of diamond films grown on Ti6Al4V alloy, Surf. Coatings Tech, 194, 271-275 2005 . 3. S.-J. Yu, M.-W. Kang, H.-C. Chang, K.-M. Chen, and Y.-C. Yu, Bright fluorescent nanodiamonds No photobleaching and low cytotoxic-ity, J. Am. Chem. Soc,...
Cvd Diamond Film And Pvd Diamondlike Carbon Dlc Coating
Diamond is also grown metastably in partial vacuum to form either freestanding films or adhered coatings. Diamond films of up to 1 mm in thickness, and up to 30 cm wide, can be precipitated by a variety of CVD methods e.g. hot filament, microwave plasma, Figure 4.17. The production cubic presses in Huanghe the largest diamond plant in the world , China that can manufacture over 3 million carats a day. Figure 4.17. The production cubic presses in Huanghe the largest diamond plant in the world ,...
Dialon Applications
Dialon may have numerous applications. For example, it can be coated on plastic material to improve the air tightness. For example, Figure 10.11. Frictional coefficient between steel ball and DLC coated high speed steel plate. Figure 10.11. Frictional coefficient between steel ball and DLC coated high speed steel plate. the interior of PET bottles can be coated with dialon by inserting the container with an electrode that echoes with the exterior electrode in radio frequency e.g. 15.6 MHz . The...
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Conductive layer thickness lt 10 nm Surface hole concentration -1013 cm 2 Hydrophobic Negative electron affinity Conductive layer thickness lt 10 nm Surface hole concentration -1013 cm 2 Hydrophobic Negative electron affinity Hydrophilic Positive electron affinity Figure 8.6. Schematic diagram of the H- and O-terminated 00 1 diamond surfaces and their physical properties. Source From Ref. 26. Diamond in Biomedical Applications 169 11 Figure 8.7. An X-ray radiogram taken after an implantation...
Liquid Phase Growth Of Diamond At Low Pressure
Gem diamond crystals have been grown by CVD methods at partial vacuum, but as graphite is the stable phase, the growth rate of diamond must be kept low lest graphitic carbons are formed. On the other hand, the growth of gem diamonds in molten alloy e.g. invar composition under ultrahigh pressure can be increased, but the volume of the apparatus is severely limited. It would be ideal if diamond can grow in liquid phase at atmospheric pressure. In this case, not only the growth rate can be high,...
Dialon Coating
The fluorinated DLC is akin to teflon that is essentially fluorine coated diamond atoms that form a single file. In fact, this structure maybe named dialon for diamond-teflon for future reference. Figure 10.9 is a schematic diagram of teflon compound. The fluorination cannot only lubricate the DLC, but also enhance its adherence to the substrate, particularly on the surface of polymers. Moreover, the fluorine atoms attached to DLC can repel water or other polarized molecules so the surface is...
The Role Of Hydrogen Atoms
In 1968, Henry Hibshman suggested that hydrogen may be used to stabilize diamond growth during the pyrolysis of carbonaceous gases. In 1971, John Angus began to duplicate Eversole's process using a hot filament process. This time he tried adding hydrogen gas to speed up the diamond growth. In 1976, Derjaquin starting experimenting the CVD growth of diamond by glow discharge. Again, he found that hydrogen addition was beneficial to his process. 1n 1981, Setaka first introduced microwave plasma...
The Split Die Technology
The belt apparatus is too bulky for making gem diamonds on one hand, and the split sphere is too complicated for making one crystal at a time. The solution is to extend the split chamber to form a longitudinal chamber that allow multiple crystal to grow simultaneously Sung, Chien-Min, US Patent No. 7,128,547 . The growth conditions of each diamond crystal can be precisely controlled by Figure 11.8. Polished artificial diamond gems with different colors. its own temperature monitor with real...
Amorphous Diamond Solar Cell
The merit of amorphous diamond to convert either light or heat to electricity can be applied to solar cell panels or thermal electrical generators. For example, amorphous diamond was over covered coated on indium tin oxide ITO , the transparent electrical conductor that was coated on a glass substrate. This panel was separated from another ITO coated glass by glass bead spacer. The gap was sealed around and the space was pumped down to high vacuum 10-6 torr . This panel was exposed to a xenon...