• Title/Summary/Keyword: Electrode

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Development of Discharge Electrode for Machining Connector Mold applying MIM Process (MIM 공법 적용 커넥터 금형 가공용 방전 전극 개발)

  • Shin, Kwang-Ho;Jeon, Yong-Jun;Heo, Young-Moo
    • Journal of the Korea Society of Die & Mold Engineering
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    • v.8 no.2
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    • pp.37-40
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    • 2014
  • A discharge electrode plays a role of shaving off workpiece with spark generated by current in discharge machining. Accordingly, for the discharge electrode, an electrode with excellent wear resistance is necessary. Generally, Graphite and Cu are used as the materials of the electrode, and recently Cu-W is mainly used as an electrode with excellent wear resistance. However, the form of the electrode generally used is produced mostly using cutting work, so a lot of costs incur if several similar forms are needed. Thus, this study developed a Cu-W electrode using Metal Injection Molding (MIM) process to produce similar forms with excellent productivity and a great quantity of electrodes in a similar form in discharge machining and carried out a discharge machining test. In developing an electrode applying MIM, predicting contraction of a product in a sintering process, a mold expansion ratio of 1.29486 was given, but the actual product showed a percentage of contraction 24% to 32%, which showed a difference of 3% to 5%. In addition, to verify wear resistance of the discharge electrode, abrasion loss was measured after the discharge.

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Effects of Electrode Shape on Electrode Life of Resistance Spot Welding of Mg Alloy (Mg 합금 저항 점 용접의 연속 타점 수명에 미치는 전극 형상의 영향)

  • Choi, Dongsoon;Kang, Moonjin;Ryu, Jaewook;Kim, Dongcheol
    • Transactions of the Korean Society of Automotive Engineers
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    • v.22 no.4
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    • pp.30-35
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    • 2014
  • According to weight lightning trend of automobile body, necessity of resistance spot welding (RSW) of Mg alloy on automobile industry is increasing rapidly because of the highest specific strength among commercial metals. Mg alloy has low electric resistance and high thermal conductivity like as Al alloy, so that needs applying high current in short time when welding. Thick oxide film of Mg alloy pollutes the electrodes and makes partial current carrying paths when on welding. Partial current carrying paths signify excessive concentration of current. There can initiate expulsion easily and reduces electrode life rapidly. Generating partial current carrying paths and expulsions are influenced by shapes of electrode. Therefore, electrode life also influenced by shape. In this study, we perform life test of RSW electrode of radius type. Measure tensile shear load and nugget size every spot alternately. As a result, radius type electrode can extend life over twice as dome type electrode.

The Usability of Zinc Electrode using Wireless Measuring System of Electric Potential (무선전위측정시스템에 사용하는 아연전극 활용성 검토)

  • Lee, Jong-Rark;Leem, Sa-Hawn;Kim, Sang-O
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • pp.177-180
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    • 2006
  • This study is to make a basic study if solid zinc (Zn) can be used for buried reference electrode, so we examined the adequacy of zinc as reference electrode by using zinc which showed regular electrode for buried period. The deference of electric potential if zinc electrode for corrosion factor such as soil resistivity or pH didn't show fixed trend and there was no clear trend on the change of measurement period. From field test, it is known that the natural electric potential difference of CSE electrode and zinc electrode is 1,100mV, but the electric potential of zinc electrode for CSE electrode in the natural soil and copying soil was 1,094~1,158mV. There was no fixed trend on the change of measurement period and electric potential difference of zinc electrode for corrosion factors such as soil resistivity or pH. Consequently, there was 40~60mV of electric potential difference in every copying soil during the experiment measurement.

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Effect of Nickel addition in DC arc test of Cu-W electrode (Cu-W 전극의 DC Arc 시험에 있어서 Nickel 첨가 영향)

  • Kim, Bong-Seo;Chung, Hyeon-Wook;Lee, Hee-Woong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.11-14
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    • 2003
  • Sintered Cu-W has been used for the electrode of GIS for interrupting the abnormal current. In this study the effect of Ni addition in Cu-W electrode was investigated. Cu-W electrodes used contains 0.1~0.2wt% Ni and were conducted the experiments which was attacked by DC arc test (70V-70A) for 300 times periodically. As the contents of Ni in Cu-W electrode increase, the hardness and electrical conductivity were decreased. The weight change ($\Delta$mg) of electrode after DC arc test increased with increasing Ni contents and test times. The hardness and electrical conductivity of electrode after DC arc test were decreased compared with non-arc affected electrode, which was owing to the defects near surface of electrode and degradation by arc heat. It was considered that Cu in the Cu-W electrode was scattered to all directions by arc heat, therefore, the electrodes were damaged and deformed in the surface and cross-section of electrode. It is difficult to estimate directly the characteristics of Cu-W electrode for GIS related with high voltage and current from the results of DC arc test conducted in this study. However, the results of the effect of Ni addition in Cu-W electrode could be applied for the research of electrode for GIS.

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A Study on the Preparation of the Dimensionally Stable Anode(DSA) with High Generation Rate of Oxidants(II) (산화제 생성율이 높은 촉매성 산화물 전극(DSA)의 개발에 관한 연구(II))

  • Park, Young-Seek;Kim, Dong-Seog
    • Journal of Environmental Science International
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    • v.18 no.1
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    • pp.61-72
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    • 2009
  • Fabrication and oxidants production of 3 or 4 components metal oxide electrode, which is known to be so effective to destruct non-biodegradable organics in wastewater, were studied. Five electrode materials (Ru as main component and Pt, Sn, Sb and Gd as minor components) were used for the 3 or 4 components electrode. The metal oxide electrode was prepared by coating the electrode material on the surface of the titanium mesh and then thermal oxidation at $500^{\circ}C$ for 1h. The removed RhB per 2 min and unit W of 3 components electrode was in the order: Ru:Sn:Sb=9:1:1 > Ru:Pt:Gd=5:5:1 > Ru:Sn=9:1 > Ru:Sn:Gd=9:1:1 > Ru:Sb:Gd=9:1:1. Although RhB decolorization of Ru:Sn:Sb:Gd electrode was the highest among the 4 components electrode, the RhB decolorization and oxidants formation of the Ru:Sn:Sb=9:1:1 electrode was higher than that of the 3 and 4 components electrode. Electrogenerated oxidants (free Cl and $ClO_2$) of chlorine type in 3 and 4 components electrode were higher than other oxidants such as $H_2O_2\;and\;O_3$. It was assumed that electrode with high RhB decolorization showed high oxidant generation and COD removal efficiency. OH radical which is electrogenerated by the direct electrolysis was not generated the entire 3 and 4 components electrode, therefore main mechanism of RhB degradation by metal oxide electrode based Ru was considered indirect electrolysis using electrogenerated oxidants.

Degradation Accelerated Stress Test of Electrode and Membrane in PEMFC (PEMFC에서 전극과 전해질 막의 열화 가속 시험)

  • Song, Jin-Hoon;Kim, Sae-Hoon;Ahn, Byung-Ki;Ko, Jai-Joon;Park, Kwon-Pil
    • Korean Chemical Engineering Research
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    • v.50 no.5
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    • pp.778-782
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    • 2012
  • Until a recent day, degradation of PEMFC MEA (membrane and electrode assembly) has been studied, separated with membrane degradation and electrode degradation, respectively. But membrane and electrode were degraded coincidentally at real PEMFC operation condition. Therefore in this work, AST (Accelerated Stress Test) of MEA degradation was done at the condition that membrane and electrode were degraded simultaneously. There was interaction between membrane degradation and electrode degradation. Membrane degradation reduced the decrease range of catalyst active area by electrode degradation. Electrode degradation reduces increase range of the hydrogen crossover current and FER (Fluoride Emission Rate) by membrane degradation.

A Basic Study of Plasma Reactor of Dielectric Barrier Discharge for the Water Treatment (수처리용 유전체장벽 플라즈마 반응기에 대한 기초 연구)

  • Kim, Dong-Seog;Park, Young-Seek
    • Journal of Environmental Science International
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    • v.20 no.5
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    • pp.623-630
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    • 2011
  • This study investigated the degradation of N, N-Dimethyl-4-nitrosoaniline (RNO, indicator of the generation of OH radical) by using dielectric barrier discharge (DBD) plasma. The DBD plasma reactor of this study consisted of a quartz dielectric tube, titanium discharge (inner) and ground (outer) electrode. The effect of shape (rod, spring and pipe) of ground electrode, diameter (9~30 mm) of ground electrode of spring shape and inside diameter (4~13 mm) of quartz tube, electrode diameter (1~4 mm), electrode materials (SUS, Ti, iron, Cu and W), height difference of discharge and ground electrode (1~15.5 cm) and gas flow rate (1~7 L/min) were evaluated. The experimental results showed that shape of ground electrode and materials of ground and discharge electrode were not influenced the RNO degradation. The thinner the diameter of discharge and ground electrode, the higher RNO degradation rate observed. The effect of height gap of discharge between ground electrode on RNO degradation was not high within the experimented value. Among the experimented parameters, inside diameter of quartz tube and gas flow rate were most important parameters which are influenced the decomposition of RNO. Optimum inside diameter of quartz tube and gas flow rate were 7 mm and 4 L/min, respectively.

The Characteristics of Superposed Ozonizer using Three-Phase Voltage (3상전압을 이용한 중첩방전형 오존발생기의 특성)

  • Kim, Yeong-Hun;Chun, Byung-Joon;Song, Hyun-Jig;Youn, Young-Dae;Lee, Kwang-Sik
    • Proceedings of the KIEE Conference
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    • pp.2259-2261
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    • 1999
  • In this paper, an ozonizer, which can generate individual and superposed silent discharge, using three-phase voltage has been designed and manufactured. The ozonizer consists of 3 electrodes(Central Electrode, Internal Electrode and External Electrode) and 2 gaps(gap between Central Electrode and Internal Electrode, gap between Internal Electrode and External Electrode). Ozone is generated according to voltage supplying method to each electrode by individual silent discharge and three-phase superposed discharge. The characteristics of ozone generation were investigated with variation of discharge power and the quantity of supplied gas($O_2$). In case of individual silent discharge, the maximum values of ozone concentration, ozone generation and ozone yield were obtained between internal electrode and external electrode, and its values were 2300[ppm], 570[mg/h] and 745[g/kWh] respectively. Each maximum values was 5039[ppm], 1773[mg/h] and 851[g/kWh] respectively, when three-phase superposed silent discharge was employed. Therefore, characteristics of ozone generation with three-phase voltage are improved compared with single-phase voltage because silent discharge is generated continuously.

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Resistance Spot Weldability of Low Density Lightweight Steel according to Electrode Shape (전극 형상에 따른 저비중 경량강판의 저항 점 용접 특성)

  • Hwang, Insung;Yoon, Hyunsang;Kim, Dongcheol;Kang, Munjin;Kim, Jae Do;Kim, Young-Min
    • Journal of Welding and Joining
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    • v.35 no.2
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    • pp.52-57
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    • 2017
  • In this study, resistance spot weldability of lightweight steel with high Al contents was evaluated using various electrode shapes. The six types of electrode shape were prepared with different electrode face diameter and radius. The tensile shear tests were carried out to investigate the failure behaviors. Also, the nugget size and hardness were measured and compared with various electrode shapes. The experimental results show that the acceptable weld current region for low density lightweight steel could be obtained with 10mm electrode face diameter and 76mm electrode face radius.

Effects of electrode configurations on uniformity of copper films on flexible polymer substrate prepared by ECR-MOCVD (ECR-MOCVD에 의해 연성 고분자 기판에 제조된 구리막의 균일도에 전극의 형태가 미치는 영향)

  • 전법주;이중기
    • Journal of the Korea Institute of Military Science and Technology
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    • v.7 no.1
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    • pp.34-46
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    • 2004
  • Copper films were prepared by using ECR-MOCVD(Electron Cyclotron Resonance Metal Organic Chemical Vapor Deposition) coupled with a DC bias system. The DC bias is connected to the electrode which placed 1∼3cm above the polymer substrate. The pulse electrical field around the electrode attracts the positive charged copper ions generated from the dissociation of copper precursor, $Cu(hfac)_2$, under ECR plasma. Condensation of supersaturated copper ions in the space between the electrode and substrate, makes it possible to deposit copper film on the polymer substrate even at room temperature. In this study, optimization of the electrode configuration was carried out in order to obtain the uniform films. The uniformity of the deposited films were closely related to the parameters of electrode geometry such as electrode shape, thickness, grid size and the spacing between electrodes. The most uniform copper film was observed with the electrode that enabled uniform electrical field distribution across the whole dimension of electrode.