• 한국자동차공학회논문집
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• 제16권1호
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• pp.93-99
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• 2008

To improve the performance of plasma-DeNOx catalyst, a research on active system was performed experimentally. Two hydrocarbons, propane and diesel, were used as a reductant in this study. First, using propane, basic performances of plasma-DeNOx catalyst such as the effects of plasma and C/N ratio were measured at the various engine operating conditions. NOx conversion of catalyst was improved as plasma power or C/N ratio was increased. Next, diesel was injected in the exhaust gas flow as a reductant. The first test using diesel as a reductant is spray visualization in a high temperature flow and spray images were utilized for analysis of posterior test results. To evaluate the effect of an injection direction, it was compared with 6 installation methods of diesel injector due to THC concentrations at the inlet of plasma. From the results, injector was installed toward downstream direction below the pipe. Then, basic performances of plasma-DeNOx catalyst with various injection quantities were measured. As an injection quantity was increased, $NO_2$ conversion of plasma reactor was increased but NOx conversion of catalyst was nearly zero. This was because NOx conversion of catalyst had slowed as time goes by due to black particles which had been adhered to the catalyst.

• Korean Chemical Engineering Research
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• 제49권6호
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• pp.710-714
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• 2011

본 연구에서는 열 플라스마 용사 코팅 법을 사용하여 고체산화물 연료전지에서 사용되는 $La_{0.8}Ca_{0.2}CrO_{3}$(LCC), $La_{0.8}Sr_{0.2}CrO_{3}$(LSC), $La_{0.8}Ca_{0.2}CrO_{0.9}Co_{0.1}O_{3}$(LCCC) 세라믹 연결재를 코팅하여 코팅 층의 특성평가를 수행하였다. 열 플라즈마 코팅에 앞서 각 세라믹 연결재 입자의 특성평가를 위해 X선 회절, 미세 구조, 입자 측정 및 비표면적 분석을 수행하였다. 세라믹 연결재 입자의 특성평가 후, 열 플라스마 용사 코팅 법을 사용하여 연료극 지지체 위에 코팅하였으며, 코팅 층의 특성을 평가하기 위해 코팅 층의 표면, 파단면 분석, 가스 누출 속도 및 전기 전도도 측정을 수행하였다. 이러한 특성 평가 결과를 바탕으로 열 플라스마 용사 코팅 법을 통해 코팅된 LCCC 코팅 층이 고체산화물 연료전지의 세라믹 연결재로서 적합함을 확인하였다.

• 기계저널
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• 제53권4호
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• pp.29-32
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• 2013

이 글에서는 부품 표면 처리 기법 중 용사(thermal spray)기술을 개략적으로 소개하고 특히, 극한 환경에 노출되는 부품의 수명을 높이기 위하여 적용되는 VPS(Vacuum Plasma Spray) 기법의 원리 및 연구 동향에 대하여 소개한다.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 1997년도 춘계학술강연 및 발표대회 강연 및 발표논문 초록집
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• pp.28-28
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• 1997

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1997년도 제26회 추계학술대회
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• pp.93-99
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• 1997

High Temperature wear behavior of plasma sprayed ZrO$_2$ and MoS$_2$, $Fe_2O_3$ coatings were investigated for high temperature wear resistance applications. The MoS$_2$, $Fe_2O_3$ added powders containing 2.5, 5.0, 7.5, 10.0 mol% of $MoS_2$, $Fe_2O_3$ for plasma spray were made by spray drying method. Wear test were performed at temperature ranges from room temperature to 600$\circ$C. The microstructural change of coatings and the worn. surface were examined by SEM and XRD. In ZrO$_2$ coating, the coefficient of friction and wear amount of room temperature to 400$\circ$C was increased with temperature and decreased with temperature over 400$\circ$C. The coefficient of friction and wear amount of MoS$_2$ added coatings were increased with temperature, but those of $Fe_2O_3$ added coatings had lower coefficient of friction and higher wear resistance than ZrO$_2$ coating.

• Corrosion Science and Technology
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• 제22권4호
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• pp.257-264
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• 2023

Ti-6Al-4V alloys are mainly used as dental materials due to their excellent biocompatibility, corrosion resistance, and chemical stability. However, they have a low bioactivity with bioinertness in the body. Therefore, they could not directly bond with human bone. To improve their applications, their bone bonding ability and bone formation capacity should be improved. Thus, the objective of this study was to improve the bioinert surface of titanium alloy substrate to show bioactive characteristics by performing surface modification using wollastonite powder. Commercial bioactive wollastonite powder was successfully deposited onto Ti-6Al-4V alloy using a room temperature spray process. It was found that wollastonite-coated layer showed homogeneous microstructure and uniform thickness. Corrosion resistance of Ti-6Al-4V alloy was also improved by plasma electrolytic oxidation treatment. Its wettability and bioactivity were also greatly increased by wollastonite coating. Results of this study indicate that both plasma electrolytic oxidation treatment and wollastonite coating by room temperature spray process could be used to improve surface bioactivity of Ti-6Al-4V alloy substrate.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2013년도 춘계학술대회 논문집
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• pp.106-106
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• 2013

C/C Composite는 비교적 낮은 온도에서 산화되어 고유의 특성을 쉽게 잃어버리게 된다. 본 연구에서는 Plasma Spray 코팅방법을 사용하여 다층 코팅층을 형성 시킨 후 $1600^{\circ}C$의 온도에서 열충격 저항성을 평가하였다.

• Tribology and Lubricants
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• 제12권3호
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• pp.33-38
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• 1996

High temperature wear behaviors of plasma-sprayed ZrO$_{2}$-$Y_{2}O_{3}$ composite coatings were investigated for high temperature wear resistance applications. The composite powders containing 20, 50, 80 vol% of alumina for plasma spray were made by spray drying method. Wear tests with composite coated specimens were performed at temperature ranges from room temperature to 800$^{\circ}$C. Wear tests were also carried out with heat treated specimens at room temperature. The microstructural change of coatings and the worn surface were examined by SEM and XRD. Sharp increase of wear loss at high temperature wear test was observed in specimens containing 50 and 80 vol% alumina. Similar trend was observed in the heat treated coatings. The measured residual stress was increased with increased alumina contents and heat treating temperatures. Residual stress induced during heat treatment appeared to be responsible to the observed harmful effect of alumina additions on the high temperature wear.

• 한국표면공학회지
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• 제49권1호
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• pp.87-91
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• 2016

The development of high performance transparent electrode with flexibility have been required for flexible electronics. Here, we demonstrate the silver nanowire and reduced graphene oxide hybrid transparent electrode for replacing brittle indium-tin-oxide electrode by spray coating technique and plasma reduction. The spray coating system is applied to deposit silver nanowire and over coated graphene oxide films and it has a great potential to scale-up. The resistance of silver nanowire transparent electrode is reduced by 10% and the surface roughness is decreased after graphene oxide coating. The over-coated graphene oxide is successfully reduced by $H_2$ plasma treatment and it is effective in increasing the environmental stability of electrode. The lifetime of silver nanowire and reduced graphene oxide hybrid electrode at $85^{\circ}C$ of Celsius degree of temperature and 85% of relative humidity has much increased.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2002년도 춘계 학술발표강연 및 논문개요집
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• pp.98-98
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• 2002