• Corrosion Science and Technology
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• 제10권2호
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• pp.65-70
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• 2011

DLC is considered as the candidate material for application of moving parts in automotive components relatively in high pressure and temperature operating conditions for its high hardness with self lubrication and chemical inertness. The properties of interlayer between the substrate and the DLC film were studied. Arc ion plating method have been employed to deposit onto substrate and sputtering method was used for synthesizing DLC onto interlayer. Among these six types of interlayer, deposited DLC film onto TiCN showed excellent value for characteristics. From the results of analysis for physical properties of DLC films, it seems that the adhesion forces were more important factors than intrinsic mechanical properties such as hardness, roughness and wear resistance of DLC films. AFM(Atomic Force Microscope) was used for understanding roughness of DLC films. Hardnesses of the coating layers were identified by nano-indentation method and adhesions were checked by scratch method.

• 한국표면공학회지
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• 제34권4호
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• pp.327-336
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• 2001

The skinpassing conditions such as roll type, roll force and roll roughness of the work roll were evaluated to give the surface properties of the galvanized steel sheets that were required for automotive and to get rid of the surface defects that caused with the bad control of galvanized coating process parameters. The surface defects of the galvanized steel sheets such as the ripple mark and the scratch were completely removed as the roll force of SPM work roll was increased and the amount of the transfer of roll surface texture to the strip was also gained a lot. The image clarity of electro discharge textured (EDT) coated steel sheets before and after painting was higher than that of the bright (BRT) and shot blasted (SBT) coated steel sheets because of higher PPI value, lower waviness and uniform surface pattern. Since micro-craters transferred on the surface of the galvanized steel sheets played a role of nucleation sites of chromate reaction, Increase of micro-craters was bring to better corrosion resistance with the increase of the roll force and the use of EDT roll at the skin pass mill.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.142-143
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• 2006

Combinatorial methods are being used increasingly to develop the next generation of polymers, coatings and adhesive formulations. Allied to this approach, a new genre of measurement and characterization methods are emerging. These characterization techniques are required to handle and take measurements from small samples. This has led to a number of uses for this technology which usefully fall between convention test specimen and micro- or nano-scale test methods. A versatile measurement platform will be presented which can offer useful indentation, puncture, compression, adhesion and scratch resistance data for a wide variety of material types and that continues to develop and evolve in capability.

• 한국표면공학회지
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• 제34권5호
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• pp.465-474
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• 2001

Type 304SS coatings were performed at 200$\square$ onto AISI 1045 carbon steel substrate using unbalanced magnetron sputtering (UBMS) with an austenitic AISI 304 stainless steel (SS) target of 100mm diameter. The total deposition pressure in the active Ar gas was 2$\times$10$^{-3}$ Torr. Coatings were done at various target power densities and bias voltages. Chemical compositions of metallic elements of the coatings were measured by energy dispersive X-rays spectroscopy (EDS). The structure and the morphology of Type 304SS coatings were investigated by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). Corrosion properties of the coated specimens were examined using electrochemical polarization measurements and electrochemical impedance spectroscopy in a deaerated 3.5% NaCl solution. The porosity rate was obtained from a comparison of the dc polarization resistance of the uncoated and coated substrates. Scratch adhesion testing was used to compare the critical loads for different coatings. XRD results showed that the sputtered films exhibit a ferritic b.c.c. $\alpha$-phase. Potentiodynamic polarization curves indicated that all samples had much higher corrosion potential and better corrosion resistance than the bare steel substrate. The corrosion performance increased with increasing power density and the adhesion was enhanced at the bias voltage of -50V. An improvement in the corrosion resistance can be obtained with a better coating adhesion. Finally, an optimized deposition condition for corrosion protection was found as $40W/cm^2$ and -50V.

• 대한치과보철학회지
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• 제42권2호
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• pp.210-225
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• 2004

Statement of problem: Implant screw loosening has been remained problem in restorative practices. Surface treatment of screw plays a role of preventing screw from loosening in implant screw mechanism. Purpose : The purpose of this study was to investigate surface characteristics of TiN and ZrN film ion plated screw with titanium and gold alloy screw and to evaluate wear resistance, surface roughness, and film adhesion on screw surface using various instruments. Material and methods : GoldTite screws and titanium screws provided by 3i (Implant Innovation, USA) and TorqTite screws or titanium screws by Steri-Oss (Nobel Biocare, USA) and gold screws and titanium screws by AVANA (Osstem Implant, korea) were selected. Ion plating which is much superior to other surface modification techniques was carried out for gold screws and titanium screws using Ti and Zr coating materials with nitrogen gas. Ion nitrided surface of each abutment screw was observed with field emission scanning electron microscopy (FE-SEM, micro-diamond scratch tester, vickers hardness tester, and surface roughness tester. Results : 1) The surface of gold screw and GoldTite is more smooth than ones of other kinds of non coated screw. 2) The ZrN and TiN coated surface is the more smooth than ones of other kinds of screw. 3) The hardness of TiN and ZrN coated surface showed higher than that of non coated surface. 4) The TiN coated titanium screw and ZrN coated gold screw have a good wear resistance and adhesion on the surface. 5) The surface of ZrN coated screw showed low surface roughness compared with the surface of TiN coated screw. Conclusion : It is considered that the TiN and ZrN coated screw which would prevent a screw from loosening can be applicable to implant system and confirmed that TiN and ZrN film act as lubricant on surface of screw due to decrease of friction for recycled tightening and loosening.

• 한국세라믹학회지
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• 제32권1호
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• pp.95-105
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• 1995

Ceria(CeO2) stabilized zirconia(CeSZ) sol was synthesized with zirconium n-butoxide Zr(OC4H9)4 and cerium nitrate hexahydrate Ce(NO3)3.6H2O as precursors and ethylacetoacetate(EAcAc) as a chelating agent under atmosphere. CeSZ films were deposited on AISI 304 stainless steel using the prepared polymeric sol by dipcoating and the coating characteristics were investigated by XRD, ellipsometry, scratch test and SEM. The CeSZ film began to crystallize from amorphous to tetragonal phase at 40$0^{\circ}C$ and it was not converted into monoclinic phase up to 100$0^{\circ}C$ by the addition of 16mol% CeO2 as a stabilizer which could suppress phase transformation of zirconia. The CeSZ films were prepared by varying the EAcAc contents and the cncentration of CeSZ sol and measured the thickness and refractive index. From these results, it was found that the EAcAc contents and concentration of CeSZ coating sol evidently affect the densification of CeSZ film. The CeSZ film coated with 0.4M CeSZ sol and heat-treated at $600^{\circ}C$ for 10min had thickness of 50nm and 17% porosity. The CeSZ film on 304 stainless steel effectively acted as a protective layer against oxidation up to 80$0^{\circ}C$ and had superior corrosion resistance in 25% H2SO4 solution for 4.5 hrs.

• 한국표면공학회지
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• 제41권4호
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• pp.147-155
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• 2008

The dental orthodontic wire provides a good combination of strength, corrosion resistance and moderate cost. The purpose of this study was to investigate the effects of TiN and ZrN coating on corrosion resistance and physical property of orthodontic wire using various instruments. Wires(round type and rectangular type) were used, respectively, for experiment. Ion plating was carried out for wire using Ti and Zr coating materials with nitrogen gas. Ion plated surface of each specimen was observed with field emission scanning electron microscopy(FE-SEM), energy dispersive X-ray spectroscopy(EDS), atomic force microscopy(AFM), vickers hardness tester, and electrochemical tester. The surface of TiN and ZrN coated wire was more smooth than that of other kinds of non-coated wire. TiN and ZrN coated surface showed higher hardness than that of non-coated surface. The corrosion potential of the TiN coated wire was comparatively high. The current density of TiN coated wire was smaller than that of non-coated wire in 0.9% NaCl solution. Pit nucleated at scratch of wire. The pitting corrosion resistance $|E_{pit}-E_{rep}|$ increased in the order of ZrN coated(300 mV), TiN coated(120 mV) and non-coated wire(0 mV).

• 폴리머
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• 제38권1호
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• pp.1-8
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• 2014

표면 색상과 모폴로지가 우레탄-아크릴 코팅 소재 표면의 긁힘 거동에 미치는 영향을 조사하였다. 동일한 실험 조건에서, 흰색, 적색, 검정색 시험편의 순으로 긁힘 저항성이 우수함을 보였다. 이런 결과는 명암 대비효과를 가지고 설명될 수 있다. 즉 검정색 시험편의 경우, 긁힘이 생성된 손상 영역은 빛을 확산 반사하여 백화현상이 일어나고, 그 결과 주변 검정색과 대비되어 더욱 뚜렷이 구별된다. 반면, 흰색 시험편은 주변 흰색이 보호색 역할을 하여, 긁힘 손상 부위를 인지하기 어렵게 된다. 광택도가 높은 시험편 표면일수록 에틸렌, 실리카 성분 및 카르보닐 그룹의 증가를 관찰할 수 있었다. 실리카 입자에 의한 표면 강성의 증가와 산화에 의한 카르보닐기 생성은 긁힘 저항성의 증가를 유도하고, 폴리에틸렌 왁스의 증가는 표면을 매끄럽게 하여 광택도의 향상에 기여한 것으로 보인다. 연구결과를 바탕으로 우레탄-아크릴 코팅 소재의 긁힘 저항성을 향상시킬 수 있는 기술적 접근 방법에 대해 토의하였다.

• 열처리공학회지
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• 제4권4호
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• pp.1-14
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• 1991

In PECVD(Plasma-Enhanced Chemical Vapor Deposition) process, titanium nitride is thin and its adhesion is poor for the protective coatings. Therefore it has been studied that intermediate layer forms between substrate and TiN thin film. Using R.F. plasma nitriding, nitride layer was first formed, then TiN thin film coated by PECVD. The chemical composition of the coatings has been characterized using AES, EDS and their crystallographic structure by means of XRD. Mechanical properties such as microhardness and film adhesion have also been determined by vickers hardness test, scratch test and indentation test. As a result, there was no difference in chemical composition and structure between the TiN deposition only and the composite of TiN deposition on nitrided steel. It was found that nitrided substrate increased the hardness of TiN coatings and was beneficial in preventing the plastic deformation in the substrate. Therefore the effective load bearing capacity of the TiN coatings on nitrided steel was increased and their adhesion was improved as well. According to the results of this study, the processes that lead to the formation of composite layers characterized by good working properties, i.e., high microhardness, adhesion and resistance to deformation.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.273-273
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• 2006

Over the past years, a large number of acrylate polymers have been developed and the overcoat thin layer containing acrylate polymers have been used for TFT-LCD color filter. As forming thin layer using acrylate polymers, the existing acrylate polymers have some problems such as low hardness by low Tg temperature, coating uniformity and solubility in organic solvent. To solve these problems, we synthesized new polymer(Scheme.), containing olefin monomer, which has high Tg temperature, good coating uniformity and good solubility in organic solvent. The overcoat thin layer containing new polymer resulted in good coating uniformity, stain, spot, scratch, heat resistance, DOP(Degree Of Planarization) on RGB glass, transparency, hardness, adhesion, anti-chemicals(anti-acid, anti-base, anti-organic solvent), insulation and anti-humidity. Scheme. The structure of new polymer X = Olefin monomer contains ketone, ester, hydroxy, ether, halogen, nitrile, alkoxy, phenyl functional group $R_1$ and $R_2$= H or $CH_3$. Ratio=0<[1/(1+m+n)]<0.7,0.1[$\leq$[n/(1+m+n)]<0.5.