• Title/Summary/Keyword: Pulse electrochemical polishing

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Study on Electrochemical Polishing for Stainless Steel using Micro Pulse Current (미세 펄스전원을 이용한 스테인레스강의 전기화학연마)

  • 이동활;박정우;문영훈
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.05a
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    • pp.127-130
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    • 2003
  • Electrolytic polishing is the anodic dissolution process in the transpassive state. It removes non-metallic inclusions and improves mechanical and corrosion resistance of stainless steel. Electrolytic polishing is normally used to remove a very thin layer of material from the surface of a metal object. An electrolyte of phosphoric, sulfuric and distilled water has been used in this study. In the low current density region, there can be found plateau region and material removal process and leveling process occur successively. In this study, an electrochemical polishing process using pulse current is adopted as a new electrochemical polishing process. In electrochemical machining processes, it has been found that pulse electrochemical processes provide an attractive alternative to the electrochemical processes using continuous current. Hence, this study will discuss the electrochemical polishing processes in low current density region and pulse electrochemical polishing.

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Study on Electrochemical Polishing for Stainless Steel 300 Series using Micro Pulse Current (미세 펄스전원을 이용한 스테인레스강 300 계열의 전기화학연마)

  • 이동활;박정우;문영훈
    • Transactions of Materials Processing
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    • v.12 no.4
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    • pp.388-393
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    • 2003
  • Electrolytic polishing is the anodic dissolution process in the transpassive state. It removes non-metallic inclusions and improves mechanical and corrosion resistance of stainless steel. Electrolytic polishing is normally used to remove a very thin layer of material from the surface of a metal object. An electrolyte of phosphoric acid 50% in vol., sulfuric acid 20% in vol. and distilled water 30% in vol. has been used in this study. In the low current density region, there can be found plateau region and material removal process and leveling process occur successively. In this study, an electrochemical polishing process using pulse current is adopted as a new electrochemical polishing process. In electrochemical machining processes, it has been found that pulse electrochemical processes provide an attractive alternative to the electrochemical processes using continuous current. Hence, this study will discuss the electrochemical polishing processes in low current density region and pulse electrochemical polishing.

AFM based Surface Verifications of Pulse Electrochemical Polishing for Various Frequency Conditions (주파수 변화에 따른 AFM 기반의 펄스 전기화학 폴리싱 표면특성 분석)

  • Kim, Young-Bin;Kim, Jong-Tye;Ahn, Dong-Gyu;Park, Jong-Rak;Jeong, Sang-Hwa;Park, Jeong-Woo
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.2
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    • pp.246-251
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    • 2012
  • Pulse electrochemical polishing process has been used to improve mechanical properties such as surface roughness and corrosion resistance on conductive metallic materials. In addition, pulse electrochemical polishing process with various frequency may produce a lustrous, smoother, deburred and cleaned surface on workpiece. The aim of this paper is to study surface characteristics of pulse electrochemical polishing for various frequency conditions using AFM to verify localized surface variation in nanometer scale.

Machining of Micro Grooves using Hybrid Electrochemical Processes with Voltage Pulses (펄스 전기화학 복합가공기술을 적용한 미세 그루브 가공)

  • 이은상;박정우;문영훈
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.9
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    • pp.32-39
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    • 2003
  • Pulse electrochemical machining process with high or low current density may produce a non-lustrous surface on workpiece surface. The usual polishing process to remove a black layer from the surface has been hand polish the part. But the milli-to-micro meter scale structure formed by the electrochemical machining process may be destroyed while polishing process. The application of ultra short voltage pulses based on the analysis of electrical double layer charging process allows high resolution electrochemical machining and polishing. This technique was based on the specific polarization resistance from the comparison of ideal and experimental potential variation during short voltage pulses.

Study on the new development of combined electrochemical processes using pulse current (마이크로 펄스 전해 복합가공에 관한 연구)

  • 박정우;이은상;문영훈
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.918-921
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    • 2002
  • Some investigators who have tried to achieve the highly smooth surface finish using electrochemical processes have reported that high current density produced lustrous surfaces while the opposite conditions produced a passive layer and had a tendency to produce a black surface. However, processing at a low current density may produce a non-lustrous surface but the improvement of dimensional accuracy of the surface is significant. The surface with pulse process was a bit more lustrous than with continuous current but the black passive layer still could be found at grooved surface. There are two ways to achieve highly smooth surface finish. One is brushing it with a brush the other is electrochemical machining (ECM) with high current. The former method is the most common polishing practice, but not only may the surface obtained differ from operator to operator, but precision smooth surface on micro grooves are difficult to obtain. The latter one recently has been used to produce a highly smooth surface after EDM process. However, the material removal rate in ECM with high current is relatively high. Hence the original shape of the micro grooves, which was formed by electrochemical micro-machining (EMM) process, may be destroyed. In this study, an electrochemical polishing process using pulse current is adopted as a possible alternative process when micro grooves formed by EMM process should be polished. Mirror-like micro grooves with lustrous and smooth surface can be produced electrochemically with pulse current because the voltage and current used can be lower than the case of continuous current. This study will discuss the accurate control of physical and electrical conditions so as to achieve mirror-like micro grooves with lustrous and smooth surface without destroying the original shape of micro grooves.

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