• International Journal of Precision Engineering and Manufacturing
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• 제7권4호
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• pp.18-22
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• 2006

Although many efforts have been made in making nanometer-sized holes, there is still a major challenge in fabricating individual single-digit nanometer holes in a more controllable way for different materials, size distribution and hole shapes. In this paper we describe our efforts to use a top down approach in nanofabrication method to make single-digit nanoholes. There are three major steps towards the fabrication of a single-digit nanohole. 1) Preparing the freestanding thin film by epitaxial deposition and electrochemical etching. 2) Making sub-micro holes ($0.2{\mu}\;to\;0.02{\mu}$) by focused ion beam (FIB), electron beam (EB), atomic force microscope (AFM), and others methods. 3) Reducing the hole size to less than 10 nm by epitaxial deposition, FIB or EB induced deposition and micro coating. Preliminary work has been done on thin films (30 nm in thickness) preparation, sub-micron hole fabrication, and E-beam induced deposition. The results are very promising.

• 세라미스트
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• 제9권6호
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• pp.24-29
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• 2006

Electron beam physical vapor deposition (EB-PVD) process has currently been applied to thermal barrier coatings (TBCs) for aircraft engines. Due to unique columnar structure, EB-PVD TBCs have advantages in resistances to thermal shock and thermal cycle for their applications, compared to films prepared by plasma spray By the EB-PVD equipment, we successfully obtained yttria-stabilized zirconia (YSZ) layer which has columnar and feather like structure including a large amount of nano size pores and gaps. The EB-PVD technique has been developed for coating functional perovskite type oxides such as (La, Sr)MnO3. Electrode properties have been improved by interface and structural control.

• 한국세라믹학회지
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• 제42권2호
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• pp.117-122
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• 2005

나노 코팅 기술로써 빠른 증착 속도와 미세구조 제어가 용이하여 항공기 엔진 부품 열차폐 코팅으로 널리 이용되는 Electron Beam Physical Vapor Deposition (EB-PVD)세라믹 코팅 기술을 연료전지 전해질 제조에 적용하였다. EB-PVD 법을 이용하여 NiO-YSZ 기판에 YSZ 전해질을 약 10$\mu$m의 두께로 짧은 시간에 코팅하였으며 증착온도에 따라 나노 구조의 표면을 가진 YSZ 막을 얻을 수 있었다. 연료전지 전해질로서의 특성을 평가하기 위하여, 같은 조건의 코팅으로 $Al_{2}O_3$기판에 전해질을 동일한 조건으로 코팅하여 전해질의 전기적 특성을 평가하였다. 또한 양극물질로서 $LaSrCoO_3$ 분말을 일반적인 스크린 프린팅 기법으로 코팅하여 EB-PVD의 코팅을 이용한 고체산화물 연료전지 제조 가능성에 대하여 논의하였다

• 한국추진공학회지
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• 제19권3호
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• pp.83-88
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• 2015

열차폐 코팅(Thermal Barrier Coating) 기술의 하나로 연구되는 전자빔(EB, Electron Beam) 증착에 사용되는 코팅재료는 증착 공정 중에 고출력의 전자빔이 조사되기 때문에, 균일코팅을 위해서는 증착 중 코팅재료의 형상유지 및 안정한 융탕 형성이 필요하며, 이를 위해 적절한 밀도와 미세구조를 갖춘 잉곳(Ingot) 형태의 코팅소스가 요구된다. 본 연구에서는 8 wt%의 이트리아($Y_2O_3$)가 안정화제로 첨가된 지르코니아(8YSZ) 조성을 활용하여, 고출력 전자빔 조사환경에 사용가능한 잉곳제조를 위해 최적의 원료분말 조건을 확보하고자 하였다. 제조된 잉곳시료들에 대한 전자빔 조사 시, 수십 마이크론과 수십 나노 크기의 입자들로 구성된 혼합형 분말로 제조된 잉곳의 경우, 나노크기의 분말만으로 제조된 경우보다 향상된 열충격 저항성을 보였다.

• 한국표면공학회지
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• 제46권6호
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• pp.258-263
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• 2013

4 mol% Yttria-stabilized zirconia (4YSZ) coatings are fabricated by Air Plasma Spray (APS) and Electron Beam Physical Vapor Deposition (EB-PVD) with top coating of thermal barrier coating (TBC). NiCrAlY based bond coat is prepared as 150 ${\mu}m$ thickness by conventional APS (Air Plasma Spray) method on the NiCrCoAl alloy substrate before deposition of top coating. Each 4YSZ top coating shows different tribological behaviors based on the inherent layer structures. 4YSZ by APS which has splat-stacked structure shows lower friction coefficient but higher wear rate than 4YSZ by EB-PVD which has columnar structure. For 4YSZ by APS, such results are expected due to the sliding wear accompanied with local delamination of splats.

• 한국표면공학회지
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• 제36권6호
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• pp.423-429
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• 2003

It has been investigated corrosion resistance and crystal structure of Zn-Cr coatings fabricated by electroplating method and electron-beam physical vapor deposition method(EB-P VD). The electroplated Zn-Cr alloy consists mainly of η'-Zn phase for the lower Cr content than 7.9 wt% Cr and ${\gamma}$'-ZnCr phase for the higher Cr content. In the Zn-Cr alloy fabricated by EB-PVD the ${\gamma}$'-ZnCr phase appeared clearly at 3 wt% Cr and it became the sole phase at 50 wt%Cr. The amount of η'-Zn phase decreased obviously with increasing Cr content when it exceeded 15 wt% Cr. The electrochemical measurement of the electroplated Zn-Cr film has shown corrosion potential of about -1000 mV. The current density of active region and the amount of dissolved Zn and Cr decreased significantly with increasing Cr content. The electrochemical characteristics of Zn-Cr alloy fabricated by EB-PVD have shown that the alloy of 50 wt% Cr had the highest corrosion potential(-500 mV) and the lowest critical passive current density than that of the electroplated.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2006년도 에너지.가스.기후변화학회 연합춘계학술대회 및 특별심포지움
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• pp.350-356
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• 2006

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2002년도 춘계학술발표회 초록집
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• pp.50-50
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• 2002

탄소 박막은 내마모, 화학적 생물학적 적합성 둥의 특성으로 언하여 많은 연구자들레 의하 여 연구되어지고 있다. 그러나 탄소 박막의 경우 높은 잔류응력과 이에 따른 낮은 밀착력으 로 언하여 증착 두께에 제한이 되어왔다. EB-PVD법을 이용하여 탄소막을 증착하는 경우 이러한 문제점을 해결하기 위하여 탄소막에 제 2의 금속원소를 첨가하거나 화합물 형태의 증착원 이용, 복합공정 (Hybrid process)을 통하여 증착 두께 의 제 한을 극복하고자 하는 연 구가 계속되고 있다. 본 연구에서는 탄소막의 잔류응력 제어와 증착 두께를 높이기 위하여 Plasma Activated E E-Beam Evaporation을 통하여 탄소막을 증착하였다. 탄소막 증착시 잔류응려과 밀착력에 대한 플라즈마의 영향올 알아보기 위하여 RF 플라즈마의 인업 전력에 따라 실험을 수행하였으며 필라멘트 전자 방출원을 이용하여 플라즈마 밀도가 미치는 영향도 알아보았다.

• 한국표면공학회지
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• 제39권4호
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• pp.147-152
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• 2006

Failure mechanisms of electron beam physical vapor deposited thermal barrier coatings(EB-PVD TBCs) that occur during thermal cyclic oxidation were investigated. The investigations include microstructural degradation of NiCrAIY bond coat, thermally grown oxides(TGOs) along the ceramic top coat-substrate interface and fracture path within TBCs. The microstructural degradation of the bond coat during cyclic oxidation created Al depleted zones, resulting in reduction of NiAl and ${\gamma}$-Ni solid solution phase. It was observed that the fracture took placed primarily within the TGOs or at the interfaces between TGOs and bond coat.

• 한국표면공학회지
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• 제34권3호
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• pp.195-205
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• 2001

The surface characteristics of Ti/TiN films coated on sintered stainless steels (SSS) by electron beam physical vapour deposition (EB-PVD) were investigated. Stainless steel compacts containing 2, 4, and 10wt%Cu were prepared by the electroless Cu-plating method, which results in increased homogenization in the alloying powder. The specimens were coated with Ti and TiN with a 1.0$\mu\textrm{m}$ thickness respectively by EB-PVD. The microstructures were investigated using scanning electron microscopy (SEM). The corrosion behaviors were investigated using a potentiosat in 0.1 M $H_2$$SO_4$, and 0.1M HCl solutions and the corrosion surface was observed using SEM and XPS. The Ti coated specimens showed rough surface compared to Ti/TiN coated specimens. Ti and Ti/TiN coated SSS revealed a higher corrosion and pitting potential from anodic polarization curves than that of Ti and Ti/TiN uncoated SSS. In addition, Ti/TiN coated SSS containing 10wt% Cu exhibited good resistance to pitting corrosion due to the formation of a dense film on the surface and the decrease in interconnected porosity by electroless coated Cu.