• Title/Summary/Keyword: Plasma test

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The Application of Plasma Nitrocarburizing and Plasma Post Oxidation Technology to the Automobile Engine Parts Shafts (자동차 엔진부품용 Shaft에 플라즈마 산질화기술 적용)

  • Jeon, Eun-Kab;Park, Ik-Min;Lee, In-Sup
    • Korean Journal of Materials Research
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    • v.16 no.11
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    • pp.681-686
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    • 2006
  • Plasma nitrocarburising and plasma post oxidation were performed to improve the wear and corrosion resistance of S45C and SCM440 steel by a plasma ion nitriding system. Plasma nitrocarburizing was conducted for 3h at $570^{\circ}C$ in the nitrogen, hydrogen and methane atmosphere to produce the ${\varepsilon}-Fe_{2-3}$(N, C) phase. Plasma post oxidation was performed on the nitrocarburized samples with various oxygen/hydrogen ratio at constant temperature of $500^{\circ}C$ for 1 hour. The very thin magnetite ($Fe_3O_4$) layer $1-2{\mu}m$ in thickness on top of the $15{\sim}25{\mu}m$ ${\varepsilon}-Fe_{2-3}$(N, C) compound layer was obtained by plasma post oxidation. A salt spray test and electrochemical testing revealed that in the tested 5% NaCl solution, the corrosion characteristics of the nitrocarburized compound layer could be further improved by the application of the superficial magnetite layer. Throttle valve shafts were treated under optimum plasma processing conditions. Accelerated life time test results, using throttle body assembled with shaft treated by plasma nitrocarburising and post oxidation, showed that plasma nitrocarburizing and plasma post oxidation processes could be a viable technology in the very near future which can replace $Cr^{6+}$ plating.

Dynamic analysis of multi-functional maintenance platform based on Newton-Euler method and improved virtual work principle

  • Li, Dongyi;Lu, Kun;Cheng, Yong;Zhao, Wenlong;Yang, Songzhu;Zhang, Yu;Li, Junwei;Shi, Shanshuang
    • Nuclear Engineering and Technology
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    • v.52 no.11
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    • pp.2630-2637
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    • 2020
  • The structure design of divertor Multi-Functional Maintenance Platform (MFMP) actuated by hydraulic system for China Fusion Engineering Test Reactor (CFETR) was introduced in this paper. The model of MFMP was established according to maintenance requirements. In this paper, Newton-Euler method and the improved virtual work principle were used, the equivalent driving force of each actuator was obtained through the equivalent Jacobian inverse matrix derived from velocity relationship among the components. The accuracy of the model was verified by ADAMS simulation. The stability control of the heavy-duty components driven by hydraulic cylinders based on Newton-Euler method and improved virtual work principle was established.

Carbon Nano-Powder Functionalization and Disperisibility with Plasma Discharge

  • Gang, Yu-Seok;Jeong, Man-Gi;Lee, Deok-Yeon;Song, Seok-Gyun;Kim, Seong-In
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.491-491
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    • 2013
  • A novel plasma system has been developed for 3-dimensional modification of the carbon nano-powders. Improvement of dispersion of these nano materials are studied by plasma discharge, not using chemical modification. The plasma process is considered to great advantages over wet chemical process due to environmental, economic viewpoint, and uniformity over the treated volume. The uniform dispersion is a critical factor for these material's nano composite applications. Using this plasma system, graphene, carbon black, and CNT was treated and functionalized. Several key discharge conditions such as Ar/H2/O2 or Ar/H2/NH3 gas ratio, treatment time, power, feeder's vibration frequency are investigated. Hydrophobic of graphene has turned some more into hydrophilic by reaction test with water, electrophoresis, surface contact angle test, and turbidity analysis. The oxygen content ratio in the plasma treated CNT has increased about 3.7 times than the untreatedone. In the case of graphene and carbon black, the oxygen- and nitrogen- content has been enhanced average 10%. O-H (N-H) peak, C-O (C-N) peak, and C=O (C=N) peak data have been detected by FTIR measurement and intensified compared to before-plasma treatment due to O2 or NH3 content.

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A Study on Acoustic Emission Characteristics through the Cyclic Thermal Test of Thermal Barrier Coating by Plasma Spray Process (플라즈마 용사법에 의한 열차폐 코팅의 열피로에 따른 AE신호 특성 연구)

  • Park J.H.;Lee K.H.;Ye K.H.;Kim S.T.;Jeon C.H.;Kim J.S.
    • 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.

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Fracture Analysis of Plasma Spray Coating by Classification of AE Signals (AE파형분류에 의한 용사코팅재의 파손해석)

  • Kim, G.S.;Park, K.S.;Hong, Y.U.
    • Journal of Power System Engineering
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    • v.6 no.3
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    • pp.24-30
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    • 2002
  • The deformation and fracture behaviors of both Al2O3 and Ni 4.5wt.%Al plasma thermal spray coating were investigated by an acoustic emission method. Plasma thermal spray coating is formed by a process in which melted particles flying with high speed towards substrate, then crash and spread on the substrate surface cooled and solidified in a very short time, stacking of the particles makes coating. A tensile test is conducted on notch specimens in a stress range below the elastic limit of substrate. A bendind test is done on smooth specimens. The waveforms of AE generated from the both test coating specimens can be classified by FFT analysis into two types which low frequency(type I) and high frequency(type II). The type I waveform is considered to corresponds exfoliation of coating layers and type II waveform corresponds the plastic deformation of notch tip. The fracture of the coating layers can estimate by AE event and amplitude, because AE features increase when the deformation generates.

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Optimization of Air-plasma and Oxygen-plasma Process for Water Treatment Using Central Composite Design and Response Surface Methodology (중심합성설계와 반응표면분석법을 이용한 수처리용 산소-플라즈마와 공기-플라즈마 공정의 최적화)

  • Kim, Dong-Seog;Park, Young-Seek
    • Journal of Environmental Science International
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    • v.20 no.7
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    • pp.907-917
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    • 2011
  • This study investigated the application of experimental design methodology to optimization of conditions of air-plasma and oxygen-plasma oxidation of N, N-Dimethyl-4-nitrosoaniline (RNO). The reactions of RNO degradation were described as a function of the parameters of voltage ($X_1$), gas flow rate ($X_2$) and initial RNO concentration ($X_3$) and modeled by the use of the central composite design. In pre-test, RNO degradation of the oxygen-plasma was higher than that of the air-plasma though low voltage and gas flow rate. The application of response surface methodology (RSM) yielded the following regression equation, which is an empirical relationship between the RNO removal efficiency and test variables in a coded unit: RNO removal efficiency (%) = $86.06\;+\;5.00X_1\;+\;14.19X_2\;-\;8.08X_3\;+\;3.63X_1X_2\;-\;7.66X_2^2$ (air-plasma); RNO removal efficiency (%) = $88.06\;+\;4.18X_1\;+\;2.25X_2\;-\;4.91X_3\;+\;2.35X_1X_3\;+\;2.66X_1^2\;+\;1.72X_3^2$ (oxygen-plasma). In analysis of the main effect, air flow rate and initial RNO concentration were most important factor on RNO degradation in air-plasma and oxygen-plasma, respectively. Optimized conditions under specified range were obtained for the highest desirability at voltage 152.37 V, 135.49 V voltage and 5.79 L/min, 2.82 L/min gas flow rate and 25.65 mg/L, 34.94 mg/L initial RNO concentration for air-plasma and oxygen-plasma, respectively.

The Study on the Effect of Plasma Pre-treatment on the Dyeing Properties and the Handle in the Environment Friendly Enzyme Finishing (친환경 효소가공에서 플라즈마 전처리가 염색성과 태에 미치는 영향)

  • Kim, Ji-Hyun
    • Journal of the Korea Fashion and Costume Design Association
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    • v.10 no.3
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    • pp.173-180
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    • 2008
  • Cotton, wool, cotton/wool blended (80:20) and tencel fabrics were treated with low temperature oxygen plasma, enzymes (cellulase or protease), or oxygen plasma-enzyme and they were examined for dyeing and handling properties for environment friendly finishing. The appropriate conditions for cellulase treatment were enzyme concentration of 3g/l, pH of 5, and $60^{\circ}C$ for one hour, and for protease treatment were enzyme concentration of 4g/l, pH of 8, and $60^{\circ}C$ for one hour. The equilibrium uptake of a direct dye on cotton changed with plasma treatment and plasma-cellulase treatment, and the rate of dyeing slightly decreased. When wool was dyed with acid dye, the equilibrium dye uptake did not change with plasma, protease treatment nor plasma-protease treatment, however, the rate of dyeing had increased with plasma-protease treatment. From these results, it is assumed that plasma attacks the surface of the fiber, and enzyme mainly affects the inner part of the fiber. Plasma treatment did not affect mechanical properties related to the handling of fabrics. The handling test showed increased extension at maxmum load(EM), tensile energy(WT) with decreased tensile resilience (RT), and the fabrics became softer but resilience decreased slightly with enzyme treatment. The bending recidity(B), hysteresis of bending moment(2HB), and hysteresis of shear force at five degrees(2HG5) decreased, however, shear stiffness(G) increased. I knew the plasma pre-treatment made fabrics softer with lower koshi(stiffness). The handling of plasma pre-treated fabrics was better than that of enzyme-treated fabrics. When we pre-treated fabrics, the handling test showed decreased coefficient of friction(MIU), geometrical roughness(SMD), while the surface of fabrics became smoother and numeri increased. Even though compression resilience(RC) increased, fukurami(bulky property) and compressive elasticity, decreased due to the linearity of compression-thickness curve(LC) and compression energy(WC).

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Characteristics on Corrosion Resistance of Medium High Carbon Low Alloy Steels using Plasma Nitriding Process (플라즈마 질화처리한 중, 고탄소저합금강의 내식성에 관한 연구)

  • 이병찬
    • Journal of Advanced Marine Engineering and Technology
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    • v.22 no.5
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    • pp.702-711
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    • 1998
  • The characteristics of corrosion resistance for the surface of medium high carbon steels and low alloy steels utilizing as manufacturing the machinery structures and machining tools and treating by plasma/ion nitriding process have been studied in terms of electrochemical polarization behav-iors including corrosion potential(Ecorr) anodic polarization trends and polarization resistance(Rp) The seven base materials showed a clear passivation behavior for the polarization tests in the ASTM standard solution 1N ${H_2){SO_4}$ Although the treated surface by plasma nitriding for the seven test materials showed a significant increase in hardness the treatment gave a detri-mental effect in corrosion resistance. The various characteristics including corrosion potential polarization curves microstructures corrosion current polarization resistance among non-treat-ed nitriding and/or soft-nitriding treated specimens have been investigated and some of the mechanisms discussed.

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Determination of Optimum Condition in Plasma Spraying Process (플라즈마용사공정에서의 최적 조건 결정에 관한 연구)

  • 최경수;박동화
    • Journal of the Korean Ceramic Society
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    • v.33 no.2
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    • pp.155-162
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    • 1996
  • A Taguchi methodology study of the plasma spraying thermal barrier coating (TBC) layer is presented. The experiment parameters were designed by a L8-style orthogonal arrays approach. A Taguchi analysis was conduc-ted through the results of the coating properties which were affected by plasma spraying parameters. Zirconia (partially stbilized with ytrria: PSZ) was sprayed on TiAl intermetallic compound substrates, The coating layer was characterized by thickness microstructure and porosity using SEM and Image analyzer. The coating quali-ties are discussed with respect to thermal barrier effect thermal cycling test6 and adhesion strength test. An optimum condition of plasma spraying process which are derived from the Taguchi analysis could be found for high quality TBC.

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FIRST OPERATING TEST OF THE 700 MHz 1 MW PROTOTYPE KLYSTRON FOR A PROTON ACCELERATOR

  • Ko, Seung-Kook;Lee, Bo-Young;Lee, Kang-Ok;Hong, Jin-Seok;Jeon, Jae-Ha;Chung, Bo-Hyun;Noh, Seung-Jeong;Chung, Kie-Hyung
    • Nuclear Engineering and Technology
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    • v.38 no.8
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    • pp.779-784
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    • 2006
  • The design, manufacturing process, and first operating test of a high power RF source for a proton accelerator are described. A klystron amplifier system has been developed for operation at 700 MHz, 1 MW and is composed of a triode type electron gun, six cavities, an RF output window, a beam collector, and an electromagnet. The prototype klystron was constructed and tested at a reduced duty to produce the designed output RF power.