• Proceedings of the Materials Research Society of Korea Conference
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• 2007.11a
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• pp.150.2-150.2
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• 2007

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.99-104
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• 1998

40$0^{\circ}C$ $H_2O$ steam 분위기에서 Zr-2,5wt%Nb 및 Zr-20wt%Nb 합금의 산화거동을 열처리조건에 따른 미세조직 관점에서 고찰하였으며, 형성된 oxide를 분석하여 산화기구를 규명하고자 하였다. Zr-Nb 합금의 산화거동은 열처리에 따라 협성된 조직상에 매우 민감하였는데, 주 조직인 a-Zr 상 보다는 $\beta$상들에 ($\beta$-Zr, $\beta$-Nb) 보다 큰 영향을 받는 것으로 보인다. $\beta$-Zr 상은 $\alpha$-Zr 상에 비해 부식저항성이 낮으며, 그 양에 관계없이 유사한 정도의 부식거동을 보인다. $\beta$-Nb 상의 경우, 미세한 크기로 적은양이 존재하는 경우 부식저항성에 별다른 영향이 없어 보이는 반면, 상당량의 $\beta$-Nb 상이 조대한 크기로 (약 0,2$\mu\textrm{m}$) 존재하는 경우 매우 불안정한 부식거동을 보였다. 이들 $\beta$상들의 낮은 산화저항성은 Nb$_2$O$_{5}$ 을 포함한 Nb 계 oxide의 형성에 주로 기인한 것으로 추정된다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2013.05a
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• pp.174-174
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• 2013

현재 자동차 강판 시장에서는 승객들의 안전 확보와 연비 향상을 위하여 자동차 강판의 경량화 및 고장력화가 급속히 진행되고 있다. 더불어 소비자는 더욱 아름답고 멋있는 외관을 추구하면서 정교한 디자인이 가능할 수 있도록 높은 성형성을 갖는 강판에 대한 요구도 또한 증대되고 있다. 따라서 강도와 성형성을 동시에 확보할 수 있는 DP형, TRIP형 등의 다양한 컨셉을 갖는 변태강화형 고장력강에 대한 개발 요구가 점점 심화되고 있으나 이들 고장력강의 상 제어를 위하여 첨가된 Si, Mn등의 성분들이 표면에 안정한 산화물을 형성하기 때문에 이러한 고장력강은 표면 품질이 열위한 것으로 보고 되고 있다. 따라서 기존 연구에서는 열처리중 표면으로 확산되어 올라오는 Si, Mn 산화물의 저감을 위하여 분위기 중 산소농도나 노점등을 조절하거나, 산화전처리, 선도금처리 등을 통하여 Si, Mn 의 표면 선택산화를 제어하여 도금 결함을 최소화하려는 연구가 많이 진행되고 있다. 그러나 이러한 연구들은 대부분 강판 표면에서의 산화/환원의 반응에 대한 분위기 요인을 제어하는 연구들이며 실제 Si, Mn등의 산화성 원소들이 어떠한 조건에서 어떠한 경로들을 통해서 이동하여 표면으로 올라오는지에 대한 연구는 부족한 상황이다. 따라서 본 연구에서는 산화성 원소들의 표면 확산 거동에 대한 고찰을 위하여 다양한 열처리 온도 조건을 통한 표면 도금성 경향, 합급화 경향 및 표면 분석결과를 바탕으로 확산 거동에 대한 경향을 밝히고자 하였다.

• Journal of the Korean Electrochemical Society
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• v.12 no.1
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• pp.34-39
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• 2009

In this study, a needle coke was oxidized in a mixture of dilute nitric acid and sodium chlorate ($NaClO_3$) solutions and followed by heat treatment. The samples were analyzed with using XRD, FESEM, elemental analyzer, BET, and Raman spectroscopy. Double layer capacitance was measured with the charge and discharge measurements. The consisting layers of the needle coke were expanded to single phase showing only (001) diffraction peak by the acid treatment for 24 hours. The oxidized coke returned to a graphite structure appearing (002) peak after heat treatment above $200^{\circ}C$. The structure returned could be more easily accessible to the ions by the first charge, and improve the double layer capacitance at the second charge. The two-electorde cell from acid treated coke and $300^{\circ}C$ heat treatment exhibited the maximum capacitances of 32.1 F/g and 29.5 F/ml at the potential of $0{\sim}2.5\;V$.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.248-248
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• 2012

실리콘 산화막 기판 및 퀄츠 기판 위에 그래핀을 기계적으로 박리시킨 후, 두께 1 nm 이하의 금 박막을 증착한 후 고온 열처리를 통하여 금 박막으로부터 나노입자의 형성 거동을 살펴보았다. 열처리 후 생성되는 금 나노입자는 실리콘 산화막 및 퀄츠기판 보다 그래핀 위에서 더 크게 형성되는 것을 확인하였으며, 이는 금의 표면확산 정도가 그래핀 위에서 더 크다는 것을 의미한다. 또한 동일 박리 그래핀 위에서도 그래핀의 층 수에 따라 형성되는 금 나노입자의 크기가 달라짐이 확인되었다. 열처리에 의해 형성된 다양한 크기의 금 나노입자는 단일벽 탄소나노튜브(SWNTs)의 직경제어 합성을 위한 촉매로 이용하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.527-536
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• 2019

This study examines the degradation of PTT BCF and fading behavior of disperse dye by heat treatment and UV irradiation. The behavior in strength degradation of PTT BCF after treat treatment was examined by measuring the tensile strength of samples. The strength retention of PTT BCF rapidly decreased with increasing exposure time at 150℃. The K/S value decreased with increasing temperature and its trend accelerated with increasing exposure time on heat. The behavior on strength degradation of PTT BCF and the fading of disperse dye on it were studied under UV irradiation at various temperatures. The tensile strength of PTT BCF and the K/S value of the sample dyed with disperse dye after UV irradiation decreased with increasing temperature and exposure time. PTT BCF exposed under UV irradiation exhibited lower strength and K/S value compared with the sample after heat treatment. Additional study on the effects of additives used to improve the resistance to fading of disperse dye and degradation of PTT BCF revealed that antioxidant and UV absorbent in PTT BCF showed a small improvement in the strength degradation of PTT BCF and the fading of dye.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.2
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• pp.88-92
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• 2003

The correlationship between heat treatment condition and electrical properties of the Mn-Co-Ni oxide NTC thermistor for fuel level sensor was investigated by the X-ray diffractometry, density measurement, and electrical properties measurement such as resistivity, B constant, and thermal dissipation constant. It was shown that the heat treatment of NTC thermistor was responsible for sinterability of Mn-Co-Ni oxide. The highest density of 5.10 g/㎤ was obtained at $1250^{\circ}C$, 2 hours, at which the densification was almost completed. This is also manifested from the microstructural observation. It is found that the electrical resistivity and B constant are increased at the elevated sintering temperatures. The NTC specimens prepared in this study showed the conventional decrease of resistance with the measured temperature and the linear behavior of output voltage with fuel levels. Therefore, the electrical properties of thermistor were closely correlated with sintering condition. and the Mn-Co-Ni oxide thermistor prepared in this study has a great possibility enough to apply for an automobile fuel level sensor.

• Proceedings of the Korean Nuclear Society Conference
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• 2002.05a
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• pp.218.2-218
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• 2002

• Korean Journal of Materials Research
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• v.3 no.6
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• pp.638-644
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• 1993

The degradation of dielectric breakdown field of 8nm-thick gate oxide ($SiO_2$) for Tipolycide MOS(meta1-oxide-semiconductor) capacitor with different annealing conditions and thickness of the polysilicon film on gate oxide was investigated. The degree of degradation in dielectric breakdown strength of the gate oxide for Ti-polycide gate became more severe with increasing annealing temperature and time, especially, for the case that thickness of the polysilicon film remained on the gate oxide after silicidation was reduced. The gate oxide degradation may be occurred by annealing although there is no direct contact of Ti-silicide with gate oxide. From SIMS analysis, it was confirmed that the degration of gate oxide during annealing was due to the diffusion of titanium atoms into the gate oxide film through polysilicon from the titanium silicide film.

• Journal of the Korean Ceramic Society
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• v.40 no.7
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• pp.652-656
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• 2003

The green emitting phosphor, BnGa$_2$O$_4$:Mn thin films with spinel structure were deposited by rf magnetron sputtering at various Ar/O$_2$ ratios. Thin film phosphors were heat-treated in air and $N_2$+vacuum atmosphere, respectively. Effects of Ar/O$_2$ ratios and annealing conditions on the structural and photoluminescence (PL) and cathodeluminescence (CL) properties were investigated. Luminous properties were more improved by inhibiting the films from contacting with oxygen during heat treatment.