• Proceedings of the Korean Environmental Sciences Society Conference
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• 2008.11a
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• pp.452-457
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• 2008

분말 TiO$_2$를 코팅한 전극은 전기저항으로 인해 0.5 A 이상의 전류를 인가할 수 없었으며, 1 A를 적용하였을 때 60분의 반응시간 후 최종 RhB 농도를 측정한 결과 Ru/Ti 전극의 RhB 농도 감소 가장 큰 것으로 나타났고, Ru/Ti > Ti > SG-TiO$_2$ > Th-TiO$_2$로 나타났다. 전기분해 공정만 적용한 경우 RhB 농도 감소의 순서는 Ru/Ti = Ti > SG-TiO$_2$ > Th-TiO$_2$ 전극의 순서로 나타났다. UV만 적용한 경우 RhB 제거는 작았으며, Ti와 Ru/Ti 전극은 UV만 적용한 경우와 RhB 제거농도가 비슷하였는데 이는 전극 표면에서 광촉매 반응이 일어나지 않는다는 것을 의미한다. 반면 TiO$_2$를 전극 표면에 형성하거나 코팅한 전극은 UV만 적용한 경우보다 RhB 농도가 낮게 나타났고, TiO$_2$가 형성되거나 코팅된 전극은 P-TiO$_2$ > Th-TiO$_2$ > SG-TiO$_2$의 순서로 나타났으나 차이는 크지 않았다. 광전기촉매 공정에서 시너지 효과가 거의 없는 것은 전극 표면에 코팅되거나 형성된 TiO$_2$의 양이 적고 광촉매 반응에 의한 분해 정도가 낮아 전자-정공의 재결합 감소효과가 적기 때문인 것으로 사료되었다. Th-TiO$_2$와 SG-TiO$_2$ 전극의 경우 전해질로 Na$_2$SO$_4$를 사용한 경우의 RhB 농도가 NaCl을 사용한 경우보다 RhB 낮게 나타났으나, Ti와 Ru/Ti 전극의 경우는 반대 현상이 나타났다. 이와 같은 결과는 광촉매 반응이 높은 Th-TiO$_2$와 SG-TiO$_2$ 전극에서의 Cl$^-$의 광촉매 반응 저해현상이 높게 나타났기 때문이라고 사료되었다. 반면 DSA 전극인 Ti와 Ru/Ti 전극의 경우 광촉매 반응이 거의 나타나지 않기 때문에 주반응인 전기분해 반응에서의 촉진 반응이 지배적이기 때문에 Th-TiO$_2$와 SG-TiO$_2$ 전극과는 정 반대의 현상이 나타났다고 사료되었다. 전기/UV 공정에서는 최적 전류는 0.75 A, NaCl 투입량은 0.5 g/L로 나타났으며, 최적 UV램프 전력은 16 W인 것으로 나타났다.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.4
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• pp.357-362
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• 2011

Purpose: The narrow-band pass color-filters with a 500 nm central wavelength and 12 nm FWHM using $Ti_3O_5/SiO_2$ mutilayer were fabricated, and their characteristics and structures were studied. Methods: the optical constants, n and k, of the $Ti_3O_5$ and $SiO_2$ thin films were obtained from the transmittances of their thin film. The narrow-band pass color-filters were designed with these optical constants and the AR coating of the filter was also designed. $Ti_3O_5/SiO_2$ multilayer filters were made by electron beam evaporation apparatus and the transmittaces of the filters were measured by spectrophotometer. the number of layers and the thicknesses of filters were calculated from the cross section of filters by SEM image and the composition of filters was analysed by XPS analysis. Results: The optimization of AR coating for the narrow-band pass color-filter was [air$|SiO_2(90)|Ti_3O_5(36)|SiO_2(5)|Ti_3O_5(73)|SiO_2(30)|Ti_3O_5(15)|$ glass], and the optimization of filter layer for the color filter was [air$|SiO_2(192)|Ti_3O_5(64)|SiO_2(102)|Ti_3O_5(66)|SiO_2(112)|Ti_3O_5(74)|SiO_2(120)|Ti_3O_5(68)|SiO_2(123)|Ti_3O_5(80)|SiO_2(109)|Ti_3O_5(70)|SiO_2(105)|Ti_3O_5(62)|SiO_2(99)|Ti_3O_5(63)|SiO_2(98)|Ti_3O_5(51)|SiO_2(60)|Ti_3O_5(42)|SiO_2(113)|Ti_3O_5(88)|SiO_2(116)|Ti_3O_5(68)|SiO_2(89)|Ti_3O_5(49)|SiO_2(77)|Ti_3O_5(48)|SiO_2(84)|Ti_3O_5(51)|SiO_2(85)|Ti_3O_5(48)|SiO_2(59)|Ti_3O_5(34)|SiO_2(71)|Ti_3O_5(44)|SiO_2(65)|Ti_3O_5(45)|SiO_2(81)|Ti_3O_5(52)|SiO_2(88)|$ glass]. It was known that the color-filters fabricated by the simulation data were composed of 41 layers by SEM image and the top layer of filters was $SiO_2$ layer and the filters were composed of $SiO_2$/$Ti_3O_5$ multilayer by XPS analysis. It was also known that the mixed thin film of TiO2 and $Ti_3O_5$ was made during the deposition of the $Ti_3O_5$ material. Conclusions: The narrow-band pass color-filters with a 500 nm central wavelength and 12 nm FWHM using $Ti_3O_5/SiO_2$ mutilayer of 41 layer were fabricated, and it was known that the mixed form of TiO2 and $Ti_3O_5$ thin film was made during the deposition of the $Ti_3O_5$ material.

• Journal of Welding and Joining
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• v.14 no.2
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• pp.46-56
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• 1996

HAZ impact toughness of Ti-oxide steel was investigated and compared to that of a conventional Ti-nitride steel. Toughness variations of each steel with weld peak temperatures and cooling rates were interpreted with microstructural transformation characteristics. In contrast to Ti-nitride steel showing continuous decrease in HAZ toughness with peak temperature, Ti-oxide steel showed increase in HAZ toughness above $1400^{\circ}C$ peak temperature. The HAZ microstructure of the Ti-oxide steel is characterized by the formation of intragranular ferrite plate, which was found to start from Ti-oxide particles dispersed in the matrix of the steel. Large austenite grain size above $1400^{\circ}C$ promoted intragranular ferrite plate formation in Ti-oxide steel while little intragranular ferrite plate was formed in Ti-nitride steel because of dissolution of Ti-nitrides. Ti-oxides in the Ti-oxide steel usually contain MnS and have crystal structures of TiO and/or $Ti_2O_3$.

• Journal of the Korean institute of surface engineering
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• v.35 no.6
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• pp.391-400
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• 2002

Corrosion characteristics of Ti, Ti/Cr coated and plasma-nitrided surface for stainless steel containing Ti have been studied. Stainless steels containing 0.09-0.92wt% Ti were fabricated by using vacuum furnace and solutionized for 1hr at 105$0^{\circ}C$. Ti and Cr coatings were done on solutionized stainless steel surface by EB-PVD. The Ti coated specimen were coated by Cr and were nitrided by plasma at $450^{\circ}C$ for 5hr. Microstructure and phase analysis were performed using SEM, OM and EDX. Corrosion behavior of the coated specimen was investigated by electrochemical test. The coated surface was of fine columnar structure. The Ti/Cr coated surface was denser than the Ti coated and the Ti coated-nitrided surfaces. The corrosion and pitting potential increased in proportion to the Ti content, coating temperature, coating thickness and formation of stable oxide film. The current density in active and passive region decreased in the case of Ti/Cr coated sample and Ti coated-nitrided samples. Especially the plasma nitrided specimen after Ti coating have a good corrosion resistance compared with the Ti coated specimen. The number and size of pits decreased as Ti content of matrix increased.

• Journal of the Korean institute of surface engineering
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• v.36 no.1
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• pp.89-98
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• 2003

Corrosion characteristics of Ti, Ti/Cr coated and plasma-nitrided surface for stainless steel containing Ti have been studied. Stainless steels containing 0.09-0.92wt% Ti were fabricated by using vacuum furnace and solutionized for 1hr at $1050^{\circ}C$. Ti and Cr coatings were done on solutionized stainless steel surface by EB-PVD. The Ti coated specimen were coated by Cr and were nitrided by plasma at $450^{\circ}C$ for 5hr Microstructure and phase analysis were performed using SEM, OM and EDX. Corrosion behavior of the coated specimen was investigated by electrochemical test. The coated surface was of fine columnar structure. The Ti/Cr coated surface was denser than the Ti coated and the Ti coated-nitrided surfaces. The corrosion and pitting potential increased in proportion to the Ti content, coating temperature, coating thickness and formation of stable oxide film. The current density in active and passive region decreased in the case of Ti/Cr coated sample and Ti coated-nitrided samples. Especially the plasma nitrided specimen after Ti coating have a good corrosion resistance compared with the Ti coated specimen. The number and size of pits decreased as Ti content of matrix increased.

• Journal of the Korean Ceramic Society
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• v.33 no.9
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• pp.995-1002
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• 1996

The TiC-(Ni/Ti) composites were prepared by reaction bonding between TiC preforms and the melted mixture of Ni/Ti metal the atomic ratio of which were the ranges of 0.3 to 3. And their microstructures phase composi-tions and mechanical properties were investigated. During reaction bonding Ni/Ti metal mixture had a good wettability an permeability with TiC preforms and pore-free and fully dense sintered bodies were fabricated. TiC particle shape changed from spherical to angular platelet-like and grain size was grown with Ni/Ti atomic ratio increasing from 0.3 to 1. whereas grain growth of TiC particle was restrained and its shape changed gain from angular platelet-like to spherical when Ni/Ti atomic ratio was more than 2. Maximum bending strength and fracture toughness were obtained at the Ni/Ti atomic ratio being 1 their values were 582 MPa and 11.1 MPa.m1/2 respectively.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2001.11a
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• pp.26-27
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• 2001

• Korean Chemical Engineering Research
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• v.50 no.1
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• pp.118-127
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• 2012

TiN or Ti/TiN was coated on stainless steel as bipolar plate in polymer electrolyte membrane fuel cells (PEMFCs) to improve their corrosion resistance and electric conductivity, and their properties were examined under fuel cell operating condition. After 200 hours operation, the behaviors for the corrosion, crack and dissolution of coating layer were investigated by various techniques. The corrosion and exfoliation of coating layer were considerably generated except for SUS316L-Ti/TiN after fuel cell operation even if the electric conductivity and corrosion resistance of coated stainless steel bipolar plates were improved. The adoption of Ti layer between TiN layer and the surface of stainless steel enhanced the adhesion of TiN layer and decreased the possibility of corrosion by the increase of coating layer.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2008.11a
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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.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2008.11a
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• pp.66-67
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• 2008

본 연구에서는 코팅된 Ni-Ti파일의 이온용출을 조사하기 위하여 표면에 형성된 TiN/Ti 및 ZrN/Ti다층막의 구강유사액에서 표면의 부식특성을 조사하였다.