• 한국표면공학회지
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• 제39권6호
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• pp.263-267
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• 2006

As technology advances, there is a demand for development of hard solid lubricant coating. (Ti, Cr, Zr)N-$MoS_2$ films were deposited on AISI H13 tool steel substrate by co-deposition of $MoS_2$ with (Ti, Cr, Zr)N using a D.C. magnetron sputtering process. The influence of the $N_2Ar$ gas ratio, the amount of $MoS_2$ in the films and the bias voltage on the mechanical and structural properties of the films were investigated. The highest hardness level was observed at the $N_2/Ar$ gas ratio of 0.3. Hardness of the films did not change much with the increase of the $MoS_2$ content in the films. As the substrate bias potential was increased, hardness level of the film reached maximum at -150 V. Surface morphology of these films indicated that high hardness was attributed to the fine dome structure.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2008년도 추계학술대회 초록집
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• pp.64-65
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• 2008

본 연구에서는 임상적으로 사용후 파절된 Ni-Ti파일의 표면 거동을 조사해보고 피로파괴수명 연장을 위하여 표면에 TiN/Ti 및 ZrN/Ti를 다층막으로 코팅한 후 표면의 특성을 조사하였다.

• 대한치과기공학회지
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• 제35권4호
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• pp.343-352
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• 2013

Purpose: The purpose of this study was to investigate to effect of the ZrN coated on corrosion resistance and physical property of dental Co-Cr alloys using various instruments. Methods: The specimens were used, respectively, for experiment, Arc Ion plating was carried out for dental casting alloys using ZrN coated materials with nitrogen gas. ZrN coated surface of each specimen was observed with field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), vickers hardness tester, and electrochemical tester. Results: The current density of ZrN coated specimen was smaller than that of non-coated specimen in 0.9% NaCl solution. Pit nucleated at scratch of specimen. The pitting corrosion resistant |$E_{max}-E_{rep}$| increased in order of ZrN coated (110 mV), and non-coated wire (100 mV). Conclusion: The corrosion potential of the ZrN coated specimen was comparatively high. the surface of ZrN coated specimen was more smooth than that of other kinds of non-coated specimen. ZrN coated surface showed higher hardness than that of non-coated surface.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.53-54
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• 2006

Ti-Zr-Ni coatings deposited by low vacuum plasma spray technique consisted of nanometer-sized $W-Ti_{50}Zr_{35}Ni_{15}$ 1/1 cubic approximant and TiZrNi Laves phases as well as a low volume fraction of $ZrO_2$ phase. The shift of composition during deposition of the quasicrystalline powders and the presence of $ZrO_2$ phases are believed to be responsible for the reduced corrosion performances evaluated by means of electrochemical tests in a Hanks' Balance Salt Solution at $37^{\circ}C$.

• 한국표면공학회지
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• 제43권6호
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• pp.260-265
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• 2010

STD 61 steel has been widely used for tools, metallic mold and die for press working because of its favorable mechanical properties such as high toughness, and creep strength as well as excellent oxidation resistance. The STD 61 tool steel coated with TiN and ZrN by sputtering results in improvement of wear and corrosion resistance. In this study, surface characteristics of TiN and ZrN film coated STD 61 by sputtering were studied by using FE-SEM, EDS, XRD, and XRR and nanoindentation tests. From the results of surface characteristics of coated specimen, the ZrN coated surface showed finer granular than that of TiN coated surface. The coated layer structures of ZrN and TiN were grown to (111) and (200) preferred orientation. From the results of XRR test for surface roughness, density and growth rate of coating film, surface roughness and growth rate of ZrN coated film revealed lower values those of TiN coated film, whereas density of ZrN coated film showed higher values than that of TiN coated film. From the nanohardness and elastic modulus test, nanohardness value and elastic modulus of ZrN coated film became higher than those of TiN coated film.

• 한국분말재료학회지
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• 제19권6호
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• pp.416-423
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• 2012

This paper introduces an effect of a preparing $ZrO_2$-Ag composite on its mechanical properties and microstructure. In present study, $ZrO_2$-Ag was prepared by reduction-deposition route and wetting dispersive milling method, respectively. Two type of Ag powders (nano Ag and micron Ag size, respectively) were dispersed into $ZrO_2$ powder during wetting dispersive milling in D.I. water. Each sample was sintered at $1450^{\circ}C$ for 2hr in atmosphere, and then several mechanical tests and analysis of microstructure were carried out by bending test, hardness, fracture toughness and fracture surface microstructure. As for microstructure, the Ag coated $ZrO_2$ showed homogeneously dispersed Ag in $ZrO_2$ in where pore defect did not appear. However, $ZrO_2$-nano Ag and $ZrO_2$-micro Ag composite appeared Ag aggregation and its pore defect, which carried out low mechanical property and wide error function value.

• 한국세라믹학회지
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• 제43권8호
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• pp.463-468
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• 2006

Hydrothermal deposition of hydroxyapatite coatings on two types of $ZrO_2$ substrates (3 mol% $Y_2O_3$-doped and 13 mol% $CeO_2$-doped tetragonal $ZrO_2s$) was studied using aqueous solutions of $Ca(NO_3)_2\;4H_2O$ and $(NH_4)_2HPO_4$ containing EDTA (ethylene diamine tetra acetic acid) disodium salt as a chelating agent for $Ca^{2+}$ ions. For the precipitation of the coatings, the $EDTA-Ca^{2+}$ chelates were decomposed by oxidation with $H_2O_2$ at $90^{\circ}C$. The deposition behavior, morphology, and orientation of the coatings were investigated while varying the solution pH using scanning electron microscopy and X-ray diffractometry. For the two sub-strates, sparse deposition of the coating was obtained at pH 5.5, whereas a uniform deposition was obtained at pH 7.1, 9.8, and 11.4 with a denser microstructure for the higher pH. The coating consisted of thin needle-like or plate-like crystals ($1-2{\mu}m$ length or diameter) at pH 7.1, but fine rod-like crystals ($1-2{\mu}m$ length, $0.1{\mu}m$ diameter) at pH 9.8 and 11.4. The coatings were $1-3{\mu}m$ thick and showed a preferred orientation of the hydroxyapatite crystals with their c axis (i.e., the elongated direction) perpendicular to the substrate surface especially for pH 9.8 and 11.4.

• 전기화학회지
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• 제20권3호
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• pp.49-54
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• 2017

본 연구에서는 리튬이차전지용 분리막으로 사용되고 있는 폴리올레핀 계열 분리막의 취약한 열 안정성을 극복하기 위해 부직포 기반의 세라믹 코팅 복합 분리막을 개발하였다. 개발된 복합 분리막은 지르코늄 다이옥사이드 ($ZrO_2$) 나노 입자와 PVDF-HFP (Polyvinylidine fluoride-hexafluoropropylene) 바인더로 구성된 세라믹 코팅층을 전기 방사로 제조된 폴리비닐알코올 (PVA) 지지체 양면에 코팅하여 제조하였다. 개발 복합 부직포 분리막의 통기도 및 전해액 함침성을 측정한 결과 상용 PE 분리막 대비 매우 낮은 Gurley값과 우수한 전해액 함침 특성을 나타냈으며 이로 인해 이온 전도성이 상용 PE 분리막 대비 크게 향상됨을 확인하였다. 또한 개발 복합 부직포 분리막의 전기화학적 특성 평가를 위해 코인셀을 제조하였고 고율 방전 실험을 수행한 결과 상용 PE 분리막 대비 고율방전 특성이 크게 향상됨이 관찰되었다. 마지막으로 개발 복합 부직포 분리막의 열적 안정성을 평가하기 위해 열 수축율 실험을 수행하였으며 그 결과 개발 복합 부직포 분리막의 열수축율이 상용 PE 분리막 대비 크게 개선되는 것을 관찰하였다.

• 한국세라믹학회지
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• 제44권10호
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• pp.580-584
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• 2007

The ZrC layer instead of SiC layer is a critical and essential layer in TRISO coated fuel particles since it is a protective layer against diffusion of fission products and provides mechanical strength for the fuel particle. In this study, we carried out computational simulation before actual experiment. With these simulation results, Zirconium carbide (ZrC) films were chemically vapor deposited on $ZrO_2$ substrate using zirconium tetrachloride $(ZrCl_4),\;CH_4$ as a source and $H_2$ dilution gas, respectively. The change of input gas ratio was correlated with growth rate and morphology of deposited ZrC films. The growth rate of ZrC films increased as the input gas ratio decreased. The microstructure of ZrC films was changed with input gas ratio; small granular type grain structure was exhibited at the low input gas ratio. Angular type structure of increased grain size was observed at the high input gas ratio.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2000년도 특별강연 및 춘계학술발표대회 개요집
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• pp.228-231
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• 2000

Based on the principle of complementary energy an analytical method is developed for determining thermal stress distribution in an thermal barrier coating. This method gives the stress distributions which satisfy the stress-free boundary conditions at the edge. Numerical examples are given in order to verify the method and to investigate the thickness effects of the ZrO$_2$-8wt％Y$_2$O$_3$ top coat on the integrity of thermal barrier coating consisted of IN738LC substrate and MCrAlY bond coat.