• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 추계학술대회 논문집
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• pp.605-606
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• 2008

• 한국표면공학회지
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• 제47권1호
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• pp.33-38
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• 2014

Nanoindentater tests were conducted to conducted nanoindentation microhardness of the individual phase of ferrite and martensite of 680MPa dual-phase (DP) steel charged with hydrogen. Hydrogen was charged by electrochemical method with current densities of 150, $200mA/cm^2$ for charging times of 5, 10, 25, 50 hours, respectively. Nanoindenter test results showed that the nanoindentation microhardnesses of ferrite phase of DP steel were varied from min. 1.58 GPa to max. 2.82 GPa, and the nanoindentation microhardnesses of martensite phase varied from min. 3.19 GPa to max. 5.16 GPa with the variation of hydrogen charging conditions. It was observed that the variations of the nanoindention microhardnesses of martenstie phase were higher than those of ferrite phases. It was thought that martensite phase in the 680MPa DP steel was more sensitive than ferrite phase to hydrogen embrittlement.

• 방사선산업학회지
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• 제4권4호
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• pp.335-339
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• 2010

In this study, the surface of polyimide (PI) films was modified using ion implantation to enhance its adhesion to a deposited copper (Cu) layer. The surfaces of the PI films were implanted with 150 keV $Xe^+$ ions at fluences varying from $1{\times}10^{14}$ to $1{\time}10^{16}ions\;cm^{-2}$. The Cu layers were then deposited on the implanted PI. The surface properties of the implanted PI film were investigated based on the contact angle measurements, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). Furthermore, the adhesive strength between the deposited Cu layer and PI film was estimated through a scratch test using a nanoindenter. As a result, the surface environment of the PI film was changed by the ion implantation, which could have a significant effect on the adhesion between the deposited Cu layer and the PI.

• 센서학회지
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• 제28권2호
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• pp.101-105
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• 2019

ZnS substrates with excellent transmittance in the mid-infrared region ($3-5{\mu}m$) were prepared using hot pressing instead of conventional chemical vapor deposition (CVD). Diamond-like carbon(DLC) was coated on either one or both sides of the ZnS substrates to improve their mechanical properties and transmittance. More specifically DLC was coated using CVD with an Ar and $C_2H_2$ mixed gas, and Ge was used as the bonding layer. During CVD, the bias voltage was fixed to 500 V and analyzed by Fourier transform infrared spectroscopy (FT-IR), nanoindenter, scanning electron microscope and energy dispersive spectrometry. Results of hardness analysis using the nanoindenter, showed that DLC coating increased from 5.9 to 17.7 GPa after deposition. The FT-IR spectroscopy results showed that, in the mid-infrared region ($3-5{\mu}m$), the average transmittance of the samples with DLC coating on one and both sides increased by approximately 6% and approximately 11.2% respectively. In conclusion, the DLC coating improved the durability and transmittance of the ZnS substrates.

• 한국세라믹학회지
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• 제40권7호
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• pp.657-661
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• 2003

잉크젯 프린터 헤드용 기능성 막으로 많이 활용하고 있는 다층박막(SiO$_2$/poly-Si/SiN/SiO$_2$, 두께, 2.77 $\mu\textrm{m}$)과 다이아몬드 박막(두께, 1.6 $\mu\textrm{m}$)을 미소 외팔보($\mu$-CLB) 형태로 가공한 후 nanoindenter를 이용한 굽힘 시험 방법으로 탄성계수와 굽힘 강도를 측정하였으며 다층막을 이루는 박막 중 SiO$_2$ 박막(두께, 1 $\mu\textrm{m}$)과 SiN 박막(두께, 0.43 $\mu\textrm{m}$)의 탄성계수를 미소 외 팔보 굽힘 시험 방법과 nanoindentation 방법으로 측정한 후 그 결과를 비교하였다. 미소 외팔보 굽힘 시험방법으로 측정한 다층막의 탄성계수와 파괴강도는 외팔보의 폭이 18.5 $\mu\textrm{m}$에서 58.5 $\mu\textrm{m}$로 증가함에 따라 각각 68.08 ㎬과 2.495 ㎬에서 56.53 ㎬과 1.834 ㎬로 감소하였다. SiO$_2$ 박막의 탄성계수 측정값은 외팔보의 폭이 29.6$\mu\textrm{m}$ 와 59.5 $\mu\textrm{m}$ 범위에서 변하여도 영향을 받지 않고 68.16$\pm$0.942 ㎬이었으며, SiN 박막의 탄성계수는 215.45 ㎬이었다. Nanoindentation 방법으로 측정한 SiO$_2$ 박막과 SiN 박막의 탄성계수는 각각 98.78 ㎬, 219.38 ㎬이었다. 이 결과로부터 미소 외팔보 굽힘 시험방법으로 측정한 박막의 탄성계수가 nanoindentation 방법으로 측정한 탄성계수와 2% 미만의 차이를 보이며 일치함을 알 수 있었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 추계학술대회 논문집
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• pp.289-290
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• 2006

• 한국재료학회지
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• 제20권4호
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• pp.194-198
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• 2010

Cubic boron nitride (c-BN) is a promising material for use in many potential applications because of its outstanding physical properties such as high thermal stability, high abrasive wear resistance, and super hardness. Even though 316L austenitic stainless steel (STS) has poor wear resistance causing it to be toxic in the body due to wear and material chips, 316L STS has been used for implant biomaterials in orthopedics due to its good corrosion resistance and mechanical properties. Therefore, in the present study, c-BN films with a $B_4C$ layer were applied to a 316L STS specimen in order to improve its wear resistance. The deposition of the c-BN films was performed using an r.f. (13.56 MHz) magnetron sputtering system with a $B_4C$ target. The coating layers were characterized using XPS and SEM, and the mechanical properties were investigated using a nanoindenter. The friction coefficient of the c-BN coated 316L STS steel was obtained using a pin-on-disk according to the ASTM G163-99. The thickness of the obtained c-BN and $B_4C$ were about 220 nm and 630 nm, respectively. The high resolution XPS spectra analysis of B1s and N1s revealed that the c-BN film was mainly composed of $sp^3$ BN bonds. The hardness and elastic modulus of the c-BN measured by the nanoindenter were 46.8 GPa and 345.7 GPa, respectively. The friction coefficient of the c-BN coated 316L STS was decreased from 3.5 to 1.6. The wear property of the c-BN coated 316L STS was enhanced by a factor of two.

• 소성∙가공
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• 제17권8호
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• pp.633-642
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• 2008

It's important to measure quantitative properties about thermal-nano behavior of polymer for producing high quality components using Nanoimprint lithography process. Nanoscale indents can be used to make the cells for molecular electronics and drug delivery, slots for integration into nanodevices, and defects for tailoring the structure and properties. In this study, formability of polymethylmetacrylate(PMMA) and polycarbonate(PC) were characterized Polymer has extreme variation in thermo mechanical variation during forming high temperature. Because of heating the polymer, it becomes softer than at room temperature. In this case it is particularly important to study high temperature-induced mechanical properties of polymer. Nanoindenter XP(MTS) was used to measure thermo mechanical properties of PMMA and PC. Polymer was heated by using the heating stage on NanoXP. At CSM(Continuous Stiffness Method) mode test, heating temperature was $110^{\circ}C,120^{\circ}C,130^{\circ}C,140^{\circ}C$ and $150^{\circ}C$ for PMMA, $140^{\circ}C,150^{\circ}C,160^{\circ}C,170^{\circ}C$ and $180^{\circ}C$ for PC, respectively. Maximum indentation depth was 2000nm. At basic mode test, heating temperature was $90^{\circ}C$ and $110^{\circ}C$ for PMMA, $140^{\circ}C,160^{\circ}C$ for PC. Maximum load was 10mN, 20mN and 40mN. Also indented pattern was observed by using SEM and AFM. Mechanical properties of PMMA and PC decreased when temperature increased. Decrease of mechanical properties from PMMA went down rapidly than that of PC.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.124-124
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• 2011

This study investigated the interaction of varied plasma power with ultralow-k toluene-tetraethoxysilane (TEOS) hybrid plasma polymer thin films, as well as changing electrical and mechanical properties. The hybrid thin films were deposited on silicon(100) substrates by plasma enhanced chemical vapor deposition (PECVD) system. Toluene and tetraethoxysilane were utilized as organic and inorganic precursors. In order to compare the electrical and the mechanical properties, we grew the hybrid thin films under various conditions such as rf power of plasma, bubbling ratio of TEOS to toluene, and post annealing temperature. The hybrid plasma polymer thin films were characterized by Fourier transform infrared (FT-IR) spectroscopy, atomic force microscopy (AFM), nanoindenter, I-V curves, and capacitance. Also, the hybrid thin films were analyzed by using ellipsometry. The refractive indices varied with the RF power, the bubbling ratio of TEOS to toluene, and the annealing temperature. To analyze their trends of electrical and mechanical properties, the thin films were grown under conditions of various rf powers. The IR spectra showed them to have completely different chemical functionalities from the liquid toluene and TEOS precursors. Also, The SiO peak intensity increased with increasing TEOS bubbling ratio, and the -OH and the CO peak intensities decreased with increasing annealing temperature. The AFM images showed changing of surface roughness that depended on different deposition rf powers. An nanoindenter was used to measure the hardness and Young' modulus and showed that both these values increased as the deposition RF power increased; these values also changed with the bubbling ratio of TEOS to toluene and with the annealing temperature. From the field emission scanning electron microscopy (FE-SEM) results, the thickness of the thin films was determined before and after the annealing, with the thickness shrinkage (%) being measured by using SEM cross-sectional images.

• 한국재료학회지
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• 제13권1호
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• pp.53-58
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• 2003

For the rib materials in PDP(plasma display panel), an effective method to improve the mechanical properties is to form a composite material by reinforcing a glass matrix with rigid fillers, such as alumina and titania powders. In this study, two types of ribs with different volume percent of fillers and with different glass matrix were tested for hardness, Young's modulus with the Berkovich indentation. As a result, cracks appeared around at the load of 1345 mN for the dense type of rib, while porous one endured until 2427 mN without any crack formation. Young's modulus and hardness decreased at the range: 90∼65 GPa, 9∼4 GPa, respectively as a function of indent load. Thus, a new method with nanoindenter represents a possible evaluation method for mechanical properties of barrier ribs.