• 한국결정성장학회지
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• 제16권3호
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• pp.101-105
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• 2006

본 연구에서는 planetary milling을 사용하여 Ti 분말과 $Si_3N_4$와의 반응이 일어나도록 하여 nano $TiN_x$을 제조하였다. 이렇게 얻어진 분말은 Ti 분말과 혼합하여 SPS 소결 장치를 이용하여 소결하였으며 이 소결체의 고온에서의 경도변화를 조사하기위해 $850^{\circ}C$에서 열처리하였다. 분말의 물성평가는 X선 회절분석을 통해 결정상의 변화를 분석하였으며, 그 결과 milling 시간이 10시간의 milling에서는 $TiN_{0.26}$과 TiN이 혼재되어 있으며 20시간의 milling에서는 주로 TiN이 생성되는 것으로 확인되었다. 제조된 분말의 표면관찰을 통해서는 milling 시간이 증가할 수로 입자표면에 새로 형성된 반응물 size 분포를 조사하였으며, milling 시간이 길수록 입자표면의 $TiN_x$ 입자의 사이즈가 $10{\sim}20nm$ 정도로 작아지는 것을 알 수 있었다. Ti와 $TiN_x$를 중량비로 50:50로 혼합하여 제조한 소결체의 경도는 마이크로비커스 경도 값으로 $1050kgf/mm^2$ 정도를 나타내었다.

• 대한금속재료학회지
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• 제47권9호
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• pp.591-596
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• 2009

$TiN_xO_y/TiN_x$ multi-layer thin films with a high resistance(${\sim}k{\Omega}$) were deposited on $SiO_2/Si$ substrates at room temperature by sputtering. The $TiN_x$ thin films show island and smooth surface morphology in samples prepared by ${\alpha}$ and RF magnetron sputtering, respectively. $TiN_xO_y/TiN_x$ multi-layer in has been developed to control temperature coefficient of resistance(TCR) by the incorporation of $TiN_x$ layer(positive TCR) inserted into $TiN_xO_y$ layers(negative TCR). Electrical and structural properties of sputtered $TiN_xO_y/TiN_x$ multi-layer films were investigated as a function of annealing temperature. In order to achieve a stable high resistivity, multi-layer films were annealed at various temperatures in oxygen ambient. Samples annealed at $700^{\circ}C$ for 1 min exhibited good TCR value of approximately $-54 ppm/^{\circ}C$ and a stable high resistivity around $20k{\Omega}/sq$. with good reversibility.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.19-19
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• 2009

TiNxOy/TiNx multilayer thin films with a high resistance (~ k$Omega$) were deposited on SiO2/Si substrates at room temperature by sputtering. The TiNx thin films show island and smooth surface morphology in samples prepared by dc and rf magnetron sputtering, respectively. TiNxOy/TiNx multilayer has been developed to control temperature coefficient of resistance (TCR) by the incorporation of TiNx layer (positive TCR) inserted into TiNxOy layers(negative TCR). Electrical and structural properties of sputtered TiNxOy/TiNx multilayer films were investigated as a function of annealing temperature. In order to achieve a stable high resistivity, multilayer films were annealed at various temperatures in oxygen ambient. Samples annealed at 700 oC for 1 min exhibit a good TCR value and a stable high resistivity.

• 한국분말재료학회지
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• 제17권2호
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• pp.123-129
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• 2010

The fabrication of interconnect from titanium powders and $TiN_x$ powders is investigated. Corrosion-resistant titanium and $TiN_x$ are used as reinforcement in order to reveal high heat and corrosion resistance at the elevated temperature. We fabricated the plates for interconnect reinforced with $TiN_x$ by mixing titanium powders with 10 wt.% of nano-sized $TiN_x$. Spark Plasma Sintering (SPS) was chosen for the sintering of these composites. The plate made of titanium powders and $TiN_x$ powders demonstrates higher corrosion resistance than that of the plate of titanium powders alone. The physical properties of specimens were analyzed by performing hardness test and biaxial strength test. The electrochemical properties, such as corrosion resistance and hydrogen permeability at high temperature, were also investigated. The microstructures of the specimens were investigated by FESEM and profiles of chemical compositions were analyzed by EDX.

• 한국표면공학회지
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• 제42권4호
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• pp.161-168
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• 2009

Effects of TiN/Ti multilayer coating on the Ti-30Ta-xZr alloy surface were studied by using various experiments. The Ti-30Ta containing Zr (5, 10 and 15 wt%) were melted 10 times to improve chemical homogeneity by using a vacuum furnace. And then samples were homogenized for 24 hrs at $1000^{\circ}C$. The specimens were prepared for TiN/Ti coating by cutting and polishing. The prepared specimens were coated with TiN/Ti multilayers by using DC magnetron sputtering method. The analyses of coated surface and coated layer were carried out by field emission scanning electron microscope(FE-SEM), EDX, and X-ray diffractometer(XRD). From the microstructure and XRD analysis of Ti-30Ta-xZr alloys, The equiaxed structure was changed to needle-like structure with increasing Zr content. And $\alpha$-peak and elastic modulus increased as Zr content increased. The $\alpha$ and $\beta$ phase predominantly were found in the specimen containing high Zr content. According to the analysis of TiN/Ti coating layer, the surface defects and structures of Ti-30Ta-xZr were covered with TiN/Ti coating layer and surface roughness decreased.

• 대한금속재료학회지
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• 제46권10호
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• pp.691-699
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• 2008

Electrochemical characteristics of Ti-30Ta-xZr alloys coated with HA/TiN by using magnetron sputtering method were studied. The Ti-30Ta containing Zr(3, 7, 10 and 15wt%) were 10 times melted to improve chemical homogeneity by using a vacuum furnace and then homogenized for 24hrs at $1000^{\circ}C$. The specimens were cut and polished for corrosion test and coating, and then coated with HA/TiN, respectively, by using DC and RF-magnetron sputtering method. The analyses of coated surface and coated layer were carried out by using optical microscope(OM), field emission scanning electron microscope(FE-SEM) and X-ray diffractometer(XRD). The electrochemical characteristics were examined using potentiodynamic (-1,500 mV~ + 2,000 mV) and A.C. impedance spectroscopy(100 kHz ~ 10 mHz) in 0.9% NaCl solution at $36.5{\pm}1^{\circ}C$. The microstructure of homogenized Ti-30Ta-xZr alloys showed needle-like structure. In case of homogenized Ti-30Ta-xZr alloys, a-peak was increased with increasing Zr content. The thickness of TiN and HA coated layer showed 400 nm and 100 nm, respectively. The corrosion resistance of HA/TiN-coated Ti-30Ta-xZr alloys were higher than that of the non-coated Ti-30TaxZr alloys, whic hindicate better protective effect. The polarization resistance($R_p$) value of HA/TiN coated Ti-30Ta-xZr alloys showed $8.40{\times}10^5{\Omega}cm^2$ which was higher than that of non-coated Ti-30Ta-xZr alloys.

• 대한화학회지
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• 제54권1호
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• pp.120-124
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• 2010

용액침전법에 의해 $TiO_2$ 및 $TiO_{2-x}N_x$를 제조하였다. $TiO_{2-x}N_x$ 시료는 순수한 $TiO_2$의 띠 간격인 3.20 eV (390 nm 흡광)로부터 1.77 eV (700 nm 흡광)까지 띠 간격이 줄어들게 되어 자외선 영역 뿐 아니라 가시광선 전체 영역에서도 흡광이 발생하였다. 가시광선에서의 광촉매 활성에서도 $TiO_{2-x}N_x$ 시료는 순수한 $TiO_2$ 및 P-25보다도 더 높은 활성도를 나타냈다.

• Corrosion Science and Technology
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• 제8권4호
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• pp.162-169
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• 2009

Pure titanium and its alloys are drastically used in implant materials due to their excellent mechanical properties, high corrosion resistance and good biocompatibility. However, the widely used Ti-6Al-4V is found to release toxic ions (Al and V) into the body, leading to undesirable long-term effects. Ti-6Al-4V has much higher elastic modulus than cortical bone. Therefore, titanium alloys with low elastic modulus have been developed as biomaterials to minimize stress shielding. For this reason, Ti-30Ta-xZr alloy systems have been studied in this study. The Ti-30Ta containing Zr(5, 10 and 15 wt%) were 10 times melted to improve chemical homogeneity by using a vacuum furnace and then homogenized for 24 hrs at $1000^{\circ}C$. The specimens were cut and polished for corrosion test and Ti coating and then coated with TiN, respectively, by using DC magnetron sputtering method. The analyses of coated surface were carried out by field emission scanning electron microscope(FE-SEM). The electrochemical characteristics were examined using potentiodynamic (- 1500 mV~+ 2000 mV) and AC impedance spectroscopy(100 kHz~10 mHz) in 0.9% NaCl solution at $36.5{\pm}1^{\circ}C$. The equiaxed structure was changed to needle-like structure with increasing Zr content. The surface defects and structures were covered with TiN/Ti coated layer. From the polarization behavior in 0.9% NaCl solution, The corrosion current density of Ti-30Ta-xZr alloys decreased as Zr content increased, whereas, the corrosion potential of Ti-30Ta-xZr alloys increased as Zr content increased. The corrosion resistance of TiN/Ti-coated Ti-30Ta-xZr alloys were higher than that of the TiN-coated Ti-30Ta-xZr alloys. From the AC impedance in 0.9% NaCl solution, polarization resistance($R_p$) value of TiN/Ti coated Ti-30Ta-xZr alloys showed higher than that of TiN-coated Ti-30Ta-xZr alloys.

• 한국안광학회지
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• 제14권1호
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• pp.57-62
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• 2009

목적: Magnetron의 세기를 비대칭으로 한 unbalanced magnetron sputtering 장치를 설계 제작하고 sus304시편 위에 TiN박막을 증착하여 색상과 경도에 관한 연구를 하고자 한다. 방법: 증착된 박막표면의 화학조성을 양적으로 분석하기 위하여 XPS high resolution scan과 curve fitting을 수행하였으며, 박막 표면의 경도를 측정하기 위해 nano indentation 장비를 이용하였다. 결과: 박막 두께가 두꺼워지면 박막의 색상은 처음에는 연한 금색, 시간이 지남에 따라 어두운 금색, 연보라, 남색으로 바뀌었다. 두께에 따른 박막의 색상변화는 박막에$TiO_{x}N_{y}$, $TiO_2$, TiN과 같은 세가지 화합물의 조성변화에 기인함을 알 수 있었으며,$ TiO_{x}N_{y}$의 조성변화가 두께에 따른 색상변화에 가장 큰 영향을 미치는 것을 여겨졌다. 결론: TiN박막의 비커스 경도가 TiN의 일반적인 경도보다 수치가 작은 것은 박막이 TiN, $TiO_2$,$TiO_{x}N_{y}$ 세가지 물질 섞여 있기 때문이라고 여겨지며, 두께에 따른 박막의 경도가 점점 커지다가 줄어드는 것은 두께에 따른 TiN 양과 밀접한 관계가 있음을 알 수 있었다.

• 한국분말재료학회지
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• 제12권4호
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• pp.273-278
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• 2005

Nanostructured TiN/$TiB_2$/$TiSi_2$ and TiN/$TiB_2$/$Ti_5Si_2$ composite powders have been prepared by mechanochemical reaction from mixtures of Ti, BN, and $Si_3N_4$ powders. The raw materials have reacted to form a uniform mixture of TiN, $TiB_2$ and $TiSi_2$ or $Ti_5Si_3$ depending on the amount of $Si_3N_4$ used in the starting mixtures, and the reaction proceeded through so-called mechanically activated self-sustaining reaction (MSR). Fine TiN and $TiB_2$ crystallites less than a few tens of nanometer were homogeneously dispersed in the amorphous $TiSi_2$ or $Ti_5Si_3$ matrix after milling for 12 hours. These amorphous matrices became crystalline phases after annealing at high temperatures as expected, but the original microstructure did not change significantly.