• 제목/요약/키워드: Coating film

검색결과 1,908건 처리시간 0.038초

Optimal Condition of Hydroxyapatite Powder Plasma Spray on Ti6Al4V Alloy for Implant Applications

  • Ahn, Hyo-Sok;Lee, Yong-Keun
    • 한국재료학회지
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    • 제22권4호
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    • pp.211-214
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    • 2012
  • Optimal conditions for HA plasma spray-coating on Ti6Al4V alloy were investigated in order to obtain enhanced bone-bonding ability with Ti6Al4V alloy. The properties of plasma spray coated film were analyzed by SEM, XRD, surface roughness measurement, and adhesion strength test because the film's transformed phase and crystallinity were known to be influential to bone-bonding ability withTi6Al4V alloy. The films were formed by a plasma spray coating technique with various combinations of plasma power, spray distance, and auxiliary He gas pressure. The film properties were analyzed in order to determine the optimal spray coating parameters with which we will able to achieve enhanced bone-bonding ability with Ti6Al4V alloy. The most influential coating parameter was found to be the plasma spray distance to the specimen from the spray gun nozzle. Additionally, it was observed that a relatively higher film crystallinity can be obtained with lower auxiliary gas pressure. Moderate adhesion strength can be achievable at minimal plasma power. That is, adhesion strength is minimally dependent on the plasma power. The combination of shorter spray distance, lower auxiliary gas pressure, and moderate spray power can be recommended as the optimal spray conditions. In this study, optimal plasma spray coated films were formed with spray distance of 70 mm, plasma current of 800 A, and auxiliary gas pressure of 60 psi.

Multi-coating법으로 제조된 두꺼운 PZT막의 두께 변화에 따른 미세구조 및 전기적 특성 (Microstructures and Electrical Properties of Thick PZT Films with Thickness Variation Fabricated by Multi-coating Method)

  • 박준식;장연태;박효덕;최승철;강성군
    • 한국재료학회지
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    • 제12권3호
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    • pp.211-214
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    • 2002
  • Properties of 52/48 PZT films with various thicknesses for piezoelectric micro-electro mechanical systems (MEMS) devices fabricated by multi-coating method on $Pt(3500{\AA})/Ti(400{\AA})/SiO_2(3000{\AA})/Si$(525$\mu\textrm{m}$) substrates were investigated. PZT films were deposited by spin-coating process at 3500 rpm for 30 sec, followed by pyrolysis at 45$0^{\circ}C$ for 10 min producing the thickness of about 120nm. These processes were repeated 4, 8, 12, 16 and 20 times in order to have various thicknesses, respectively. Finally, they were crystallized at $650^{\circ}C$ for 30 min. All thick PZT films showed dense and homogeneous surface microstructures. Thick PZT films showed crystalline structures of random orientations with increasing thickness. Dielectric constants of thick PZT films were increased with increasing film thickness and reached 800 at 100kHz for 2.3$\mu\textrm{m}$ thick PZT film. $P_r\; and\; E_c$ of 2.3$\mu\textrm{m}$ thick PZT films were about 20$\mu$C/$\textrm{cm}^2$ and 63kV/cm. Depth profile analysis by Auger Electron Spectroscopy (AES) of 4800 $\AA$ thick PZT film showed the formation of the perovskite phase on Pt layer by Pb diffusion behavior. It was considered that Pb-Pt intermediate layer promoted PZT (111) columnar structures.

Anti-Fogging, Photocatalytic and Self-Cleaning Properties of TiO2-Transparent Coating

  • ;김정식
    • 한국재료학회지
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    • 제31권1호
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    • pp.8-15
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    • 2021
  • Transparent, photocatalytic, and self-cleaning TiO2 thin film is developed by TiO2 sol-gel coating on glass and polycarbonate (PC) substrates. Acetyl acetone (AcAc) suppresses the precipitation of TiO2 by forming a yellowish (complex) transparent sol-gel. XPS analysis confirms the presence of Ti2p and O1s in the thin films on glass and PC substrates. The TiO2-sol is prepared by stabilizing titanium (IV) isopropoxide (TTIP) with diethylamine and methyl alcohol. The addition of AcAcsilane coupling solution to the TiO2-sol instantaneously turns to yellowish color owing to the complexing of titanium with AcAc. The AcAc solution substantially improves the photocatalytic property of the TiO2 coating layer in MB solutions. The coated TiO2 film exhibits super hydrophilicity without and with light irradiation. The TiO2 thin film stabilized by adding 8.7 wt% AcAc shows the highest photo-degradation for methylene blue (MB) solution under UV light irradiation. Also, the optimum photocatalytic activity is obtained for the 8.7 wt% AcAc-stabilized TiO2 coating layer calcined at 450 ℃. The thin-films on glass exhibit fast self-cleaning from oleic acid contamination within 45 min of UV-light irradiation. The appropriate curing time at 140 ℃ improves the anti-fogging and thermal stability of the TiO2 film coated on PC substrate. The watermark-free PC substrate is particularly beneficial to combat fogging problems of transparent substrates.

섬유 기반의 다공성 윈도우를 가지는 박막 제작 및 공배양에의 활용 (Fabrication of a Polymeric Film with Nanofiber-based Porous Window and Its Application to Co-culture)

  • 정영훈;이종완;진송완
    • 한국기계가공학회지
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    • 제13권2호
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    • pp.21-27
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    • 2014
  • Recently, various biochip environments have been presented. In this study, a novel transparent film with porous membrane windows, which is an essential component in a co-cultured biochip environment, is fabricated using spin-coating, 3D printing, and electrospinning processes. In detail, a transparent polystyrene film was fabricated by means of the spin-coating process followed bywindow cutting, after which apolycaprolactone-chloroform solution was deposited along the window edge to introduce an adhesion layer between the PS film and the PCL nanofibers. Nanofibers were electrospun into the window region using a direct-write electrospinning method. Consequently, it was demonstrated that the fabricated window film could be used in a co-culture biochip environment.

라미네이팅 필름의 코로나 처리 효과와 주사 전자현미경을 이용한 해석 (The Effect of Corona Treated on Laminating Film and Its Analytical Study by SEM)

  • 김종규;김양평
    • 한국인쇄학회지
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    • 제26권2호
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    • pp.15-30
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    • 2008
  • Studies were carried out the phenomenal observation on the effect of corona treated hotmelt laminating film in process of manufacture by 2 kinds of experiments. These are as follow: 1) In order to verify the treatment reducing value of dynes and dynes durability with the lapse of time, it was checked dynes of a pair of 4 bar discharge electrode with 9 one for 144 hr., and it show results that 9 bar discharge electrode has higher initial dynes as well as keep up 48 dynes durability long than 4 one. 2) Drawn an inference from 3 actions -Chemical-Physical-Mechanical, on laminating film in terms of SEM's observation that are the adhesive status in boundary of corona treated base film, extrusion coating hotmelt layer, and configuration of hotmelt surface after corona treated. In tandem system, EVA layers adhesion keep its stability without corona discharge treatment.

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액체로켓 엔진 연소기의 열차폐 코팅 및 막냉각 조건에 따른 냉각 성능 변화 해석 (Effect of Thermal Barrier Coating and Film Cooling Condition on the Cooling Performance of Liquid-propellant Rocket Engine Combustor)

  • 조미옥;김성구;최환석
    • 한국추진공학회지
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    • 제18권2호
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    • pp.52-59
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    • 2014
  • 액체로켓 엔진 연소기에 대한 연소/냉각 성능 통합 해석 및 연소 시험 결과와의 비교를 통하여 내열 세라믹 열차폐 코팅 조건에 따른 냉각 성능 변화 경향을 고찰하였다. 연소기 헤드부 근처에서의 막냉각 적용 여부 및 막냉각 유량에 따른 냉각수 온도 및 열차폐 코팅 표면 온도 변화 경향 또한 확인하였다. 본 연구를 통하여 재생냉각 방식 로켓 엔진 연소기의 냉각 기구 설계 시 고려 사항이 검토되었으며, 향후 지속적인 해석 도구 검증이 수행될 예정이다.

플라즈마 용사 및 열처리 공정을 통한 Bi-2212/2223 초전도체 thick film 제조의 기술 개발 (Technique development of Bi-2212/2223 superconductor thick film manufacturing by plasma spraying and heat treatment)

  • Lee, Seon-Hong;Cho, Sang-Hum;Ko, Young-Bong;Park, Kyeung-Chae
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2005년도 추계학술발표대회 개요집
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    • pp.262-264
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    • 2005
  • $Bi_{2}Sr_{2}CaCu_{2}O_{x}$(Bi-2212) and $Bi_{2}Sr_{2}Ca_{2}Cu_{3}O_{y}$(Bi-2223) high-$T_{c}$ superconductor(HTS) coating have been prepared by plasma spraying and heaat treatment. The Bi-2212 HTS coating later is synthesized through the peritectic reaction between Sr-Ca-Cu oxide coating layer and Bi-Cu oxide coating later, and $Bi_{2}Sr_{2}CaCu_{2}O_{y}$(Bi-2212) superconducting phase grow by partial melting process. The superconducting characteristic depends strongly on the conditions of the partial melting process. the Bi-2212 HTS layer consists of the whiskers grown in the diffusion direction. Above the 2212 layer, Bi-2223 phase and secondary phase was observed. The secondary phase is distributed uniformly over the whole surface. This is caused to the microcrack on the coatings surface. Despite everything, the film shows superconducting with an onset $T_{c}$ of about 115K. There are two changes steps. One changes (1step) at 115K is due to the diamagnetism of the Bi-2223 phase and the other changes (2step) at 78K is due to the diamagnetism of the Bi-2212 phase.

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자외선 경화코팅 필름-기질 계면에서의 주름현상에 대한 연구 (Experimental Studies of Wrinkle Formation in the UV Cured Coating Around Film-Substrate Insterface)

  • 홍진후;이행우
    • 대한화학회지
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    • 제38권7호
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    • pp.480-484
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    • 1994
  • 자외선 경화코팅 필름-기질 계면에서의 견딤성에 대하여 조사하였다. 특히, UV 경화 우레탄 아크릴레이트계 배합물에서 모노머 및 올리고머의 코팅필름 주름현상에 미치는 영향은 조사하였다. 실험결과, 주름현상은 DMTA이 손실모듈러스 피크가 넓고 shouldr가 있을수록 덜 나타났다. 특히, 변성된 방향족 우레탄 아크릴레이트를 지방족계에 첨가하므로서 hard하면서도 flexible한 코팅필름을 얻을 수 있음을 알 수 있었다. 따라서 주름현상 방지효과는 높은 손실모듈러스값 때문인 것으로 나타났다. SEM 및 instron 실험결과도 위의 결론을 입증하고 있음을 알 수 있었다.

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Spin-coating에 의한 $Ge_{20}As_{20}Se_{60}$ 비정질 chalcogenide 박막의 제조 및 광특성 분석 (Preparation and Characterization of $Ge_{20}As_{20}Se_{60}$ Amorphous Chalcogenide Thin Film by Spin Coating)

  • 이강구;최세영
    • 한국세라믹학회지
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    • 제37권3호
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    • pp.219-226
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    • 2000
  • Amorphous Ge20As20Se60 chalcogenide thin films were prepared by spin coating technique from mixed solutions of As40Se60 and Ge40Se60 dissolved in ethylenediamine. Films were prepared at a roating speed of 3500 rpm and spinning time was 10 second and heat-treateed at 27$0^{\circ}C$ for 1 hour. The resulting film thickness and RMS roughness were approximately 340 nm and 15$\AA$. Photostructure changes were investigated with 514.5nm Ar+ laser irradiation and heat-treatment. After Ar+ laser irradiation, transmittance and transmission efficiency decreased respectively up to 24.9% at 2.43 eV and 67.5% at 3.27 eV, and absorption edge shifted toward long wavelength. Optical bandgap changed from 2.03 to 1.83 eV, and absoprtion coefficient and absorption efficiency increased up to 0.33$\times$105cm-1 at 3.37eV and 88.3% at 1.31 eV, respectively. These photodarkening state were recovered reversibly by heat-treatment at 27$0^{\circ}C$ for 1 hour. Photodarkening and thermal bleaching effects by laser irradiation and heat-treatment revealed reversible amorphous-to-amorphous transition varying only coordination number.

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