• Journal of Welding and Joining
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• v.7 no.2
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• pp.25-34
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• 1989

The purpose of this work is to coat ZrO$_{2}$ - 8Y$_{2}$O$_{3}$ ceramic on the Al cast alloy(AC-8A) by using the plasma spray method. Two types of coatings which were composed of two and three layer coating were examined. Each coating powder was analyzed for shape and size distribution and X-ray diffraction pattern. For the coated layers, microstructural analysis and performance estimation which was composed of static thermal test, thermal cyclic test and thermal shock test were conducted.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.61-62
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• 2014

To evaluate anti-corrosion performance of high-frequency arc metal spray film in accordance with metal type and epoxy sealing coat application status, electrochemical impedance spectroscopy(EIS) method was conducted in this study. As a result, in case of applying Al-Mg alloy metal spray film, it showed the best polarization resistance. In case of applying epoxy sealing coat, it showed increased polarization resistance of arc metal spray film. Through this experiment, it is judged that Al-Mg alloy arc metal spray film with epoxy sealing coat can increase the biggest anti-corrosion performance of high-frequency arc metal spray film on steel.

• Journal of Welding and Joining
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• v.21 no.2
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• pp.9-19
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• 2003

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.43-43
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• 2010

반도체 및 디스플레이의 진공부품은 알루미늄 모제에 전해연마법(electrolytic polishing), 양극산화피막법(anodizing), 플라즈마 용사법(plasma spray) 등을 사용하여 $Al_2O_3$ 피막을 성장시켜 사용되고 있다. 반도체 제조공정 중 30~40% 이상의 비중을 차지하는 식각(etching) 및 증착(deposition) 공정의 대부분 은 플라즈마에 의해 화학적, 물리적 침식이 발생하여 피막에 손상을 일으켜 피막이 깨지거나 박리되면서 다량의 particle을 생성함으로써 생산수율에도 문제를 야기 시킨다. 본 연구에서는 이러한 진공부품의 하나인 etcher용 상부전극을 양극산화피막법(Anodizing)으로 $Al_2O_3$ 피막을 성장시킨 샘플을 제작하여 플라즈마 처리에 따른 내전압, 식각율, 표면 미세구조의 변화를 관찰하였고 이를 종합적으로 고려하여 etcher용 상부전극의 Life Time 평가 방법을 연구하였다. 이러한 실험을 통해 플라즈마 처리 후 피막에 크랙이 발생되는 것을 확인할 수 있었고 피막의 손상으로 전기적 특성이 감소되는 것을 확인할 수 있었다. 또한 플라즈마 처리 중 ISPM 장비를 이용하여 플라즈마 공정에서 발생하는 오염입자를 실시간으로 측정할 수 있는 방법을 연구하였다. 이러한 결과를 이용하여 진공공정에서 사용되는 코팅부품이 플라즈마에 의한 손상정도를 정량화 하고 etcher용 상부전극의 Life Time 평가 방법을 개발하여 부품 양산업체의 진공장비용 코팅부품의 개발 신뢰성 향상이 가능할 것으로 기대된다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.4
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• pp.61-68
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• 2019

As the pollution of water resources deteriorates due to industrialization and urbanization, it is difficult to supply clean water through a water treatment method using chlorine. Therefore, the introduction of advanced water treatment facilities using ozone is on the increase. However, epoxy which is used as waterproofing and anticorrosives and stainless steel used in conventional waterproofing and anti-corrosive methods have deteriorated because of the strong oxidizing power of ozone, causing problems such as leaking. Moreover, it even causes the durability degradation of a concrete. Therefore, in this study, metal spraying system was used as the means of constructing a metal panel with excellent ozone resistance and chemical resistance which is an easier method than an existing construction method. Ozone resistance was evaluated in accordance with the type of metal sprayed coatings to develop a finishing method which can prevent the concrete structure of water treatment facilities from deterioration. Furthermore, electrochemical stability in actual sewage treatment plant environment was evaluated. Experimental results showed that Ti has superior ozone resistance after spraying and the electrochemical stability in the sewage treatment plant environment showed that Ti has the highest polarization resistance of $403.83k{\cdot}{\Omega}{\cdot}cm^2$, which ensures high levels of durability.

• Korean Journal of Materials Research
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• v.9 no.7
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• pp.724-734
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• 1999

The adhesion characteristics of the thermoplastic resins such as PE, PP PVC, PET and PS were investigated on the surfaces of conventional steel (SS41), steel (SS41P) treated with ultrasonic waves and the SS41P coated with several ceramic powders (SS41PC) by the plasma spray. Alumina (Al$_2$O$_3$), alumina titania (Al$_2$O$_3$95%, TiO$_2$ 5%) and zirconia yttria (ZrO$_2$ 95%, $Y_2$O$_3$5% ) were used for the materials plasma spray The morphologies, surface hardness, surface roughness, and contact angles on SS41, SS41P, and SS41PC were examined. The tensile shear strength and peel strength of the polymers which were attached to the surfaces of ceramics coated on SS41P also were measured. The tensile shear strength and peel strength of polymers adhered to ceramic surface coated on steel were found to be stronger than those of conventional steel. The tensile shear strength and peel strength of the polymers adhered on the surfaces of ceramics coated steel increased in the following order PE > PET > PP > PS > PVC. The high adhesion strength of PE may be attributed to the surface roughness and its anchor effect on the ceramic surface.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1349-1352
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• 2005

This paper is to investigate a defect for thermal barrier coating layers by acoustic emission method in 4-point bending test. The two-layer thermal barrier coating is composed of $150\mu{m}\;CoNiCrAlY\;bond\;coating\;by\;vacuum\;plasma\;spray(VPS)\;process\;and\;250\mu{m}\;ZrO_2-8wt%Y_2O_3$ ceramic coating layer by air plasma spray(APS) process on Inconel-718. The specimen prepared by cyclic thermal test(500, 1000, 2000cycle) at $1050^{\circ}C$ The AE monitoring system is composed of PICO type sensor, a wide band pre-amplifier(40dB), PC and AE DSP(16/32 PAC) board. The AE event, amplitude, Cumulative energy and count of coating specimens is evaluated according to cyclic thermal test.

• Journal of Power System Engineering
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• v.2 no.3
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• pp.41-48
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• 1998

This study was aimed at development of fabrication process of functionally graded materials(FGM), consisting of metal and ceramic by thermal spraying method. NiCrAIY/$Al_2O_3$ FGM were made by using plasma spraying onto the SS400 carbon steel substrate. And mechanical properties such as microhardness, thermal shock resistance and adhesive strength of the coating layer were investigated. Adhesive strength was evaluated by acoustic emission method. It was resulted that NiCrAIY/$Al_2O_3$ FGM made by thermal spraying method showed excellent thermal shock resistance and adhesive strength compared to the other lamellar structures of sprayed coatings and that AE is useful tool to evaluate the defect of thermal sprayed coating layer.

• Journal of Ocean Engineering and Technology
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• v.24 no.1
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• pp.161-165
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• 2010

In the present study, process optimization for thermal-sprayed STS316 coating has been performed using $L_9(3^4)$ orthogonal array and analysis of variance (ANOVA). STS316 coatings were fabricated by flame spray process on steel substrate, and the hardness test and microstructure observation of the coatings were studied. The results of hardness test were analyzed by ANOVA. The ANOVA results showed that the spray distance had the greatest effect on hardness of the coating, on the other hands, the effects of oxygen gas flow and spray distance were ignorable. From these results, the optimal combination of the flame spray parameters could be derived, and confirmation experiment was carried out to verify these derived results. The calculated hardness of the coatings by ANOVA was found to approximately close to that of confirmation experimental result. Thus, it was considered that design of experiments using orthogonal array and ANOVA was effective for process optimization of thermal-sprayed STS316 coating.

• Proceedings of the KWS Conference
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• 2010.05a
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• pp.32-38
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• 2010

Hybrid material(ceramic+metal) processes were developed for micro filter using ceramics coating at metal filter surface by thermal spray method, micro hole drilling at ceramic coated filter surface by femtosecond laser, and fiber laser direct welding of ceramic and metal (SUS304, SM45C) by capillary effect. Thermal spray process was used for ceramic powders and metal filters. The used ceramic powders were $Al_2O_3+40TiO_2$(Metco 131VF) powder of maximum particle size $5{\mu}m$ and ${Al_2O_3}99+$(Metco 54NS) power of maximum particle size 45m. Ceramic coated filters using thermal spray method had a great influence on powder material, particle size and coating thickness but had a fine performance as a micro filter. CW fiber laser was used to drill the top ceramic layer and melt the bottom metal layer for joining applications.