• Journal of the Korean Ceramic Society
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• v.31 no.9
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• pp.1060-1068
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• 1994

Stable zirconia sol was prepared from zirconium butoxide Zr(OC4O9)4 as a precursor and ethylacetoacetate(EAcAc) or diethylene glycol(DEG) as a chelating agent under ambient agent under ambient atmosphere by Sol-Gel process. The sythesized sol was coated on 304 stainless steel substrate by dip coating, thereafter zirconia film could be obtained by heat-treatment at $600^{\circ}C$. The characteristics of coating film were determined by FT-IR, XRD, and ellipsometion peak represented Zr-O-Zr bonding of tetragonal phase was shown at 470cm-1. Crystallization of zirconia gel and film from amorphous state to tetragonal phase started at 40$0^{\circ}C$, and then transformed into monoclinic phase around $700^{\circ}C$. Zirconia film coated on 304 stainless steel substrate showed relatively low porosity of 16% when it was coated with 0.4M zirconia sol and thereafter heat-treated at 80$0^{\circ}C$ and the film was densified continuously up to 90$0^{\circ}C$. The zirconia film of 10 nm thick acted as a protective layer against oxidation up to $700^{\circ}C$.

• Journal of the Microelectronics and Packaging Society
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• v.9 no.1
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• pp.49-52
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• 2002

This study demonstrated the feasibility of tape casting method to fabricate soda borosilicate glass-coated stainless steel electrostatic chucks(ESC) for low temperature semiconductor processes. Glass coating on the stainless steel substrate was 125 $\mu\textrm{m}$ thick. The adhesion of glass coating was found to be excellent such that it was able to withstand temperature cycling to over $300^{\circ}C$ without cracking and delamination. The electrostatic clamping pressure generally followed the theoretical voltage-squared curve except at elevated temperatures and high applied voltages. The deviations at elevated temperatures and high applied voltages are due to increased leakage current as the electrical resistivity of glass coating drops.

• Journal of the Korean institute of surface engineering
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• v.51 no.5
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• pp.297-302
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• 2018

The important drawback of hardware fasteners consisted of 304 stainless steel (STS) is a frequent galling caused by a combination of friction and adhesion between the sliding surface. To improve the anti-galling effect, Sn-Al coatings by a thermal diffusion have been developed. The thermal diffusion by pack cementation with an $AlCl_3$ activator at $250^{\circ}C$ for 1 hour produced an Sn-Al alloy coating layer with an average thickness of $9.9{\pm}0.5{\mu}m$ on the surface of 304 STS fasteners. Compared with the galling frequency of the 304 STS fasteners, Sn-Al coatings on the surface of 304 STS fasteners demonstrated about 2.8-time reduction of the galling frequency.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.9
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• pp.121-126
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• 2009

Stainless steel 316L (STS 316L) is widely used as a material of biopsy needle. However it has a side effect that tissue can be damaged by electrochemical operation between tissue and STS 316L. Many studies have been made on the ceramic coating of biopsy needle to reduce the side effect. In this study, STS 316L was coated with three bioceramics, $Al_2O_3$, $SiO_2$ and $ZrO_2$ using a RF magnetron sputtering method. The effects of ceramic coating on the electrical conductivity and coating strength of ceramic-coated STS 316L were investigated. The results showed that the electrical conductivity of ceramic-coated STS 316L was much lower than that of uncoated STS 316L. The coating strength of $ZrO_2$-coated STS 316L was 30% and 70% higher, respectively than those of $Al_2O_3$-coated STS 316L and $SiO_2_3$-coated STS 316L.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.3
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• pp.283-291
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• 2011

Polymer electrolyte membrane fuel cells (PEMFCs) use the bipolar plate of various materials between electrolyte and contact electrode for the stable hydrogen ion exchange activation. The bipolar plate of various materials has representatively graphite and stainless steel. Specially, stainless steels have advantage for low cost and high product rate. In this study, SUS 316 was effectively coated with 600 nm thick F-doped tin oxide (SnOx:F) by electron cyclotron resonance-metal organic chemical vapor deposition and investigated in simulated fuel cell bipolar plates. The results showed that an F-doped tin oxide (SnOx:F) coating enhanced the corrosion resistance of the alloys in fuel cell bipolar plates, though the substrate steel has a significant influence on the behavior of the coating. Coating SUS 316 for fuel cell bipolar plates steel further improved the already excellent corrosion resistance of this material. After coating, the increased ICR values of the coated steels compared to those of the fresh steels. The SnOx:F coating seems to add an additional resistance to the native air-formed film on these stainless steels.

• Journal of Powder Materials
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• v.28 no.5
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• pp.396-402
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• 2021

Stainless steel, a type of steel used for high-temperature parts, may cause damage when exposed to high temperatures, requiring additional coatings. In particular, the Cr₂O₃ product layer is unstable at 1000℃ and higher temperatures; therefore, it is necessary to improve the oxidation resistance. In this study, an aluminide (Fe₂Al₅ and FeAl₃) coating layer was formed on the surface of STS 630 specimens through Al diffusion coatings from 500℃ to 700℃ for up to 25 h. Because the coating layers of Fe₂Al₅ and FeAl₃ could not withstand temperatures above 1200℃, an Al₂O₃ coating layer is deposited on the surface through static oxidation treatment at 500℃ for 10 h. To confirm the ablation resistance of the resulting coating layer, dynamic flame exposure tests were conducted at 1350℃ for 5-15 min. Excellent oxidation resistance is observed in the coated base material beneath the aluminide layer. The conditions of the flame tests and coating are discussed in terms of microstructural variations.

• The korean journal of orthodontics
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• v.51 no.4
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• pp.270-281
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• 2021

Objective: The aim of this in vitro study was to evaluate the changes in friction between orthodontic brackets and archwires coated with aluminum oxide (Al₂O₃), titanium nitride (TiN), or chromium nitride (CrN). In addition, the resistance of the coatings to intraoral conditions was evaluated. Methods: Stainless steel canine brackets, 0.016-inch round nickel-titanium archwires, and 0.019 × 0.025-inch stainless steel archwires were coated with Al₂O₃, TiN, and CrN using radio frequency magnetron sputtering. The coated materials were examined using scanning electron microscopy, an X-ray diffractometer, atomic force microscopy, and surface profilometry. In addition, the samples were subjected to thermal cycling and in vitro brushing tests, and the effects of the simulated intraoral conditions on the coating structure were evaluated. Results: Coating of the metal bracket as well as nickel-titanium archwire with Al₂O₃ reduced the coefficients of friction (CoFs) for the bracket-archwire combination (p < 0.01). When the bracket and stainless steel archwire were coated with Al₂O₃ and TiN, the CoFs were significantly lower (0.207 and 0.372, respectively) than that recorded when this bracket-archwire combination was left uncoated (0.552; p < 0.01). The friction, thermal, and brushing tests did not deteriorate the overall quality of the Al₂O₃ coatings; however, some small areas of peeling were evident for the TiN coatings, whereas comparatively larger areas of peeling were observed for the CrN coatings. Conclusions: Our findings suggest that the CoFs for metal bracket-archwire combinations used in orthodontic treatment can be decreased by coating with Al₂O₃ and TiN thin films.

• Journal of the Korean institute of surface engineering
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• v.15 no.4
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• pp.208-217
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• 1982

To study the effect of TiC coating on weight change, microhardness, wear and heat - resistance of TiC layer, chemical vapour deposition on the various substrates has been carried out with the gaseous mixture of TiCl4, toluene, and H2 in the temperature range of 900 - 1000$^{\circ}C$. The results obtained are as follows ; (1) There is a limited value of carrier and reductant H2 gas flow rate, above which deteriorate effect on the TiC depoition arises (2) Increased thickness of TiC layer was resulted with increasing temperature and time. Better deposition was obtained with stainless steels and the best results were introduced by cobalt coating of substrates. (3) Wear resistance of the TiC coated specimen improved markedly. Heat resistivity of the coated steel showed excellent result, whereas the coated stainless Steels were infer-ior to the substrate.

• New & Renewable Energy
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• v.4 no.1
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• pp.31-36
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• 2008

Stainless steels have been widely considered as metallic bipolar plates, due to their passive surface film, which is good for corrosion resistance. However, the high resistivity of the passive film increases interfacial contact resistance between the bipolar plates and the electrodes. Stainless steels thermal spray coated with a mixture of tungsten carbide and stainless steel powders showed that the coated layer safely combined with the matrix but they suffered many internal defects including voids and cracks. Many cracks were formed in the coated layer and the interface of the matrix and the coated layer during the rolling process. The coated and rolled stainless steels showed lower interfacial contact resistance and corrosion resistance than bare stainless steel because of low resistivity of tungsten carbide and numerous defects, which caused crevice corrosion, in the coated layer.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.1-5
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• 2008

Stainless steels have been widely considered as metallic separators, due to their passive surface film, which is good for corrosion resistance. However, the high resistivity of the passive film increases interfacial contact resistance between the separators and electrodes. Stainless steels thermal spray coated with a mixture of tungsten carbide and stainless steel powders showed that the coated layer safely combined with the matrix but they suffered many internal defects including voids and cracks. Many cracks were formed in the coated layer and the interface of the matrix and the coated layer during the rolling process. The coated and rolled stainless steels showed lower interfacial contact resistance and corrosion resistance than bare stainless steel because of low resistivity of tungsten carbide and numerous defects, which caused crevice corrosion, in the coated layer.