• The Korean Journal of Ceramics
• /
• v.1 no.4
• /
• pp.185-190
• /
• 1995

Tribological behavior of the diamond-like carbon (DLC) films sliding on floppy disk has been investigated. Hydrogenated DLC films have been prepared by plasma enhanced chemical vapor deposition (PECVD) using methane and hydrogen mixture in different volume ratios on ferrite substrates. DLC films show lower friction coefficients (0.2~0.4) than those of the uncoated ferrite(0.4~0.5). DLC films containing more hydrogen exhibit higher wear resistance. To investigate the roughness effect on wear, the substrates were polished with SiC papers prior to deposition. Too fine or too rough DLC surfaces result in poor wear resistance. Wear resistance of annealed DLC films at higher temperature slightly increases with respect to as-deposited film.

• Journal of the Korean Vacuum Society
• /
• v.7 no.3
• /
• pp.248-254
• /
• 1998

DLC(Diamond-Like-Carbon) thin film, one of the solid state amorphous carbon films, has been deposited by the method of PECVD (Plasma Enhanced Chemical Vapor Deposition). The structural features have been characterized using both FT-IR Spectroscopy and Raman Scattering. The film is considered to consist of microcrystalline diamond domains and graphitelike carbon domains, which are interconnected by hydrogenated $sp^3$ tetrahedral carbons. This shows a good agreement with the results by I-Vmeasurements. In I-Vstudy, the sudden increase of current has been observed and this phenomenon is understood to be due to the tunneling effect between graphitelike domains. A characteristic feature related to the $\beta$-SiC has been identified in the study of Raman Scattering for the very thin film, which suggests that a buffer layer forms at the interface of the Si substrate and the carbon film.

• Journal of the Korean Vacuum Society
• /
• v.21 no.4
• /
• pp.193-198
• /
• 2012

In this study, we have fabricated the polymer insulator and diamond-like carbon (DLC) thin films by using plasma enhanced chemical vapor deposition methods. we fabricated the DLC films with various thicknesses as the passivation layer on plasma polymer and investigated the structural, physical, and electrical properties of DLC/plasma polymer films. The plasma polymer synthesized in this work had the low leakage current and low dielectric constant. The values of hardness and elastic modulus in DLC/plasma polymer films are increased, and the value of rms surface roughness is decreased, and contact angle value is increased with increasing DLC film thickness. In the electrical properties of DLC/plasma polymer, the value of the dielectric constant is increased, however the leakage current property of the DLC/plasma polymer is improved than that of plasma polymer film with increasing DLC film thickness.

• Journal of the Korean institute of surface engineering
• /
• v.35 no.2
• /
• pp.122-128
• /
• 2002

This study was conducted to synthesize the diamond like carbon films by plasma enhanced chemical vapor deposition (PECVD). The effects of gas composition on growth and mechanical properties of the films were investigated. A little amount of hydrogen or oxygen were added to base gas mixture of methane and argon. Methane dissociation and diamond like carbon nucleation were enhanced by installing negatively bias grid near substrate. The deposited films were indentified as hard diamond like carbon films by micro-Raman spectroscopy. The surface and fractured cross section of the films which were observed by scanning electron microscopy showed that film growth is very slow as about 0.3$\mu\textrm{m}$/hour, and relatively uniform with hydrogen addition. Vickers hardness of tungsten carbide (WC) cutting tool increased from about 1000 to 1600~1800 by deposition of DLC film, that of commercial TiN coated tool was about 1270. In cutting test of aluminum 6061 alloy, DLC coated cutting tool showed 1/3 or lower crater and flank wear than TiN coated or non-coated WC cutting tools.

• Journal of the Korean Vacuum Society
• /
• v.13 no.4
• /
• pp.157-163
• /
• 2004

Dependence of residual compressive stress of diamond-like carbon (DLC) films on relative humidity was investigated. Polymeric, graphitic and diamond-like carbon films were prepared by r.f.-PACVD using methane or benzene with the negative self bias voltage of the substrate ranging from -100 to -800 V. In-situ measurements of the residual stress were carried out in an environment chamber where the relative humidity was varied from 10％ to 90％. In dense DLC film of high residual compressive stress and hardness, we could not observe any change in the residual compressive stress with relative humidity. However, in the cases of graphitic and polymeric DLC films, abrupt change in the residual stress occurred by changing the relative humidity. The quantity of the stress change was inversely proportional to the film thickness, which means that the stress change with humidity is not due to the penetration of the water molecule into the film structure, but due to surface interaction between water molecules and film surface.

• Journal of the Korean Vacuum Society
• /
• v.10 no.2
• /
• pp.194-200
• /
• 2001

In this study, the optical properties of diamond-like carbon(DLC) films, which was synthesized by 13.56 MHz rf plasma enhanced chemical vapor deposition system(PECVD), were investigated. We observed the variation of the transmittance and optical band gap with respect to deposition condition. The change of the transmittance and optical band gap of the DLC films were investigated as a function of RF power, working pressure, and additional gas. The optical band gap decreased with the increase of RF power and working pressure. We could verify the bond structures change of DLC films by observing the content of hydrogen using FT-IR spectroscopy. And the addition of hydrogen and nitrogen decreased the optical band gap by the breakage of C-H bond of DLC films during the deposition.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.11a
• /
• pp.526-529
• /
• 2002

We studied the nematic liquid crystal (NLC) aligning capabilities by the UV alignment method on a diamond like carbon (DLC) thin film surface. A good LC alignment by UV exposure on the DLC thin film surface at $200\AA$ of layer thickness was achieved. Also, a good LC alignment by the UV alignment method on the DLC thin film surface was observed at annealing temperature of $180^{\circ}C$. However, the alignment defect of the NLC was observed above annealing temperature of $200^{\circ}C$. Consequently, the good thermal stability of LC alignment by the UV alignment method on the DLC thin film surface can be achieved.

• Korean Journal of Materials Research
• /
• v.22 no.10
• /
• pp.552-561
• /
• 2012

Diamond-like carbon (DLC) films have been widely used in many industrial applications because of their outstanding mechanical and chemical properties like hardness, wear resistance, lubricous property, chemical stability, and uniformity of deposition. Also, DLC films coated on paper, polymer, and metal substrates have been extensively used. In this work, in order to improve the printing quality and plate wear of polymer printing plates, different deposition conditions were used for depositing DLC on the polymer printing plates using the Pulsed DC PECVD method. The deposition temperature of the DLC films was under $100^{\circ}C$, in order to prevent the deformation of the polymer plates. The properties of each DLC coating on the polymer concave printing plate were analyzed by measuring properties such as the roughness, surface morphology, chemical bonding, hardness, plate wear resistance, contact angle, and printing quality of DLC films. From the results of the analysis of the properties of each of the different DLC deposition conditions, the deposition conditions of DLC + F and DLC + Si + F were found to have been successful at improving the printing quality and plate wear of polymer printing plates because the properties were improved compared to those of polymer concave printing plates.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.19 no.4
• /
• pp.9-15
• /
• 2020

Carbon fiber reinforced plastic (CFRP) is a composite material useful in the aerospace and automotive industries because of its light weight and high strength. In this study, side milling tests were carried out using AlCrN, diamond-like carbon (DLC), and diamond-coated end mills. Additionally, a comparison study according to the cobalt content was conducted. Thus, tool wear and surface quality were examined and the influences of using coating and a certain material type were analyzed. The surface roughness of the machined surface was measured. Microscope observations revealed that the CFRP fiber at the machined surface was not damaged even at a cutting distance of 3,000 mm. Therefore, this study showed that the diamond-coated end mill containing 6% cobalt is appropriate for milling CFRP.

• Journal of the Korean institute of surface engineering
• /
• v.44 no.5
• /
• pp.190-195
• /
• 2011

Diamond-like carbon (DLC) has many outstanding properties such as low friction, high wear resistance and corrosion resistance. However, it is difficult to achieve enough adhesion on the metal substrates because of weak bonding between DLC film and the metal substrate. The purpose of this study is to enhance an adhesion of DLC film. For improving adhesion, the substrate was treated by active screen plasma nitriding before DLC film deposing. Nitrided substrates were investigated by Glow Discharge Spectrometer (GDS), Micro-Vickers Hardness. DLC films were deposited on several metals by linear ion source, and characteristics of the films were investigated using nano-indentation, Field Emission Scanning Electron Microscope (FESEM). The adhesion was measured by scratch tester. The adhesion of DLC films was increased when nitriding layer was formed before DLC deposition. Therefore, the adhesion of DLC film can be enhanced as increasing the hardness of materials.