• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.461-466
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• 1999

Diamond-like carbon(DLC) films were directly deposited onto germanium(Ge) witness pieces and lenses by a capacitively coupled 13.56 MHz RF glow discharge plasma with $CH_4$ gas. The characterizations of DLC films were measured using a Raman and FTIR spectrometer. The configuration of Raman and FTIR spectra had a traditional shape. The IR transmittance was measured using an IR spectrophotometer. The maximum values of the IR transmission of Ge with the DLC/Ge/DLC, DLC/Ge/BBAR (broad band antireflection), DLC/Ge, and BBAR/Ge structures are 98%, 93%, 64%, and 63.5%, respectively, which come up to the theoretical values. The uniform DLC films were obtained by a rotation of the cathode at certain conditions.

• Journal of the Korean institute of surface engineering
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• v.52 no.3
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• pp.163-170
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• 2019

Durability of instrument is one of the most important factor to ensure accurate treatment and decrease failure for the orthopedic surgical operation. Normally, a set-screw driver tip has been processed with hard coating for their higher durability and wear resistance. And several surface modification methods were obtained such as titanium nitride (TiN) coating, diamond like carbon coating, other nitriding, and etc. In this study, we have surface modified on set-screw driver tip with TiN and DLC, investigated whether the TiN and DLC coatings affect the mechanical properties and durability of the set-screw driver tip in the pedicle screw system. The surface morphologies were observed with scanning-electron microscopy (SEM), and the static/dynamic torsional properties were investigated with universal testing machine based on ASTM F543. Coating thickness of each coatings were commonly around $1^{\circ}C$. Static torsional stiffness, and ultimate torque values for DLC and TiN coated samples were significantly higher than those of non-coated sample by the pared T-test. Surface morphology of after the dynamic torsional test was more clean with less scratch or friction traces from DLC coating than that of TiN coating and non-coated sample.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.137-138
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• 2002

The benefits of using DLC coatings on steel in dry sliding are well known. The present study has investigated the effects of using the same materials but in a boundary lubricated environment. Tribological tests were performed using a load-scanning device and a lubricant with an extreme-pressure (EP) additive. XPS and grazing incidence XRD are used for chemical analysis. The chemical composition of the resulting tribofilm is correlated to different friction behaviors and contact loads, and indicates that high loads are beneficial for formation of low friction tribofilm.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.262-262
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• 2012

Diamond like carbon(DLC) 박막은 고경도, 초저마찰 특성을 요구하는 마찰분야에 널리 사용되며, 대면적 저가 코팅 방법 개발 및 물성 조절 기술이 요구된다. 본 연구에서는 선형 이온 소스를 통한 DLC 박막의 대면적 코팅 방법은 연구했으며, 방전 주파수 조절에 따른 박막 물성 조절 특성을 분석하였다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.11a
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• pp.108-109
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• 2012

DLC 박막은 고경도 및 저마찰의 우수한 물리적 특성을 갖는 것으로 널리 알려져 다양한 산업분야에 적용이 되고 있다. 또한, 그 응용 분야 확대를 위해 DLC 박막의 후막화, 대면적 균일처리, 경제성 확보 등의 연구 노력이 지속되고 있다. 특히, DLC 박막은 높은 내부응력에 의해 후막화가 어렵고, 탄소와 수소의 화학적 결합에 의한 고형 물질로 내열성이 다른 경질코팅 물질 보다 취약하다는 단점을 갖고 있다. 본 연구는 DLC 박막의 내부응력 완화를 위해 실리콘 및 질소 원소를 함유하여 박막을 제작하고, 제작 공정 조건이 박막의 물성에 미치는 영향을 연구하였다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.5
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• pp.77-83
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• 2022

A high-hardness tool material is required to reduce extreme abrasive wear when drilling carbon fiber reinforced plastic (CFRP). Single-crystal diamond is the hardest material in the world, but it is very expensive to be used as a cutting tool. Polycrystalline diamond (PCD) is a diamond grit fused at a high temperature and pressure, and diamond-like carbon (DLC) is an amorphous carbon with high hardness. This study compares DLC coatings and PCD inserts to conventional TiAlN-coated tungsten carbide drills. In fiberglass and carbon fiber reinforced polymer drilling, the tool wear of DLC-coated carbide was approximately half that of TiAlN-coated tools, and slight tool wear occurred in the case of PCD insert end drills.

• Corrosion Science and Technology
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• v.23 no.3
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• pp.235-245
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• 2024

DLC coatings have been widely applied in industrial fields that require high corrosion resistance due to their excellent mechanical characteristics and chemical stability. In this research, effects of DLC coating thickness and defects on corrosion resistance were investigated for application of metallic bipolar plates in polymer membrane electrolyte fuel cells (PEMFCs). Results revealed that a DLC coating thickness of 0.7 ㎛ could lead to a defect size reduction of about 75.9% compared to that of 0.3 ㎛.As a result of potentiodynamic polarization experiments, the current density under a potential of 0.6 V was measured to be less than 1 ㎂/cm²,which was an excellent value. Inparticular, the delamination ratio and the decrease rate of maximum pitting depth were up to 84.8% and 63.3%, respectively, with an increase in the DLC coating thickness. These results demonstrate that DLC coating thickness and defects are factors that can affect corrosion resistance of DLC coating and its substrate.

• Tribology and Lubricants
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• v.23 no.4
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• pp.170-174
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• 2007

Wear and scuffing tests were conducted using friction and wear measurement of piston rings and cylinder blocks in low friction diesel engine. The frictional forces, wear amounts and cycles to scuffing in boundary lubricated sliding condition were measured using the reciprocating wear tester. The cylinder blocks were used as reciprocating specimens, and the piston rings with several coatings were used as fixed pin. Several coatings were used such as DLC, TiN, Cr-ceramic and TiAlN in order to improve the tribological characteristics. From the tests wear volume of piston ring surfaces applied various coatings were compared. During the tests coefficients of friction were monitored. Test results showed that DLC coatings showed good tribological properties. TiN and Cr-ceramic coated rings showed good wear resistance properties but produced high friction.

• Journal of the Korean Society for Heat Treatment
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• v.23 no.2
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• pp.75-82
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• 2010

A new advanced combined PVD/CVD technique of DLC film deposition has been developed. Deposition of a DLC film was carried out using a pulsed carbon arc discharge in vapor hydrocarbon atmosphere. The arc plasma enhancing CVD process promotes dramatic increase in the deposition rate and decrease of compressive stress as well as improvement of film thickness uniformity compared to that obtained with a single PVD pulsed arc process. The optical spectroscopy investigation reveals great increase in radiating components of $C_2$ Swan system molecular bands due to acetylene molecules decomposition. AFM, Raman spectroscopy, XPS and nano-indentation were used to characterize DLC films. The method ensures obtaining a new superhard DLC nano-material for deposition of protective coatings onto various industrial products including those used in medicine.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.187-188
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• 2012

본 연구에서는 자동차 연료분사 장치의 내마모성 및 내구성 개선을 목적으로 이온빔 증착법을 이용하여 DLC 코팅을 증착하고 특성을 평가하였다. 특히 $CH_4/C_2H_2$ 분압비에 따라 DLC 박막의 표면조도, 밀착력, 경도등에 미치는 영향을 조사하였으며 DLC 박막의 구조 변화를 관찰하였다. 제조된 박막의 표면조도는 AFM (Atomic Force Microscopy)을 이용하였으며 박막의 밀착력은 스크래치 시험기를 이용하였고 미소 경도는 나노 인덴테이션을 이용하였으며 구조분석은 Raman spectroscopy를 이용하였다. 표면조도 결과 $C_2H_2$ 주입량을 증가함에 따라 표면조도와 경도값은 급격하게 증가하였고 $C_2H_2$만 주입했을 경우 Ra값이 90 nm, 미소 경도값은 2291 Hv로 최대값을 나타내었다.