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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/10/23 11:37:50」(JST)

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Electropolishing, also known as electrochemical polishing or electrolytic polishing (especially in the metallography field), is an electrochemical process that removes material from a metallic workpiece. It is used to polish, passivate, and deburr metal parts. It is often described as the reverse of electroplating. It may be used in lieu of abrasive fine polishing in microstructural preparation.^[1]

Mechanism[edit]

Electropolishing principle :
1. Electrolyte
2. Cathode
3. Workpiece to polish (Anode)
4. Particle moving from the workpiece to the cathode
5. Surface before polishing

6. Surface after polishing

Typically, the workpiece is immersed in a temperature controlled bath of electrolyte and serves as the anode as it is connected to the positive terminal of a DC power supply, the negative terminal being attached to the cathode. A current passes from the anode, where metal on the surface is oxidized and dissolved in the electrolyte, to the cathode. At the cathode, a reduction reaction occurs, which normally produces hydrogen. Electrolytes used for electropolishing are most often concentrated acid solutions having a high viscosity, such as mixtures of sulfuric acid and phosphoric acid. Other electropolishing electrolytes reported in the literature include mixtures of perchlorates with acetic anhydride and methanolic solutions of sulfuric acid.

To achieve electropolishing of a rough surface, the protruding parts of a surface profile must dissolve faster than the recesses. This process, referred to as anodic leveling, is achieved by a mass transport limited dissolution reaction.^{[clarification needed]} Anodic dissolution under electropolishing conditions deburrs metal objects due to increased current density on corners and burrs.

Applications[edit]

Electropolishing has many applications in the metal finishing industry because of its simplicity and it can be applied to objects of complex shape. Typical examples are electropolished stainless steel drums of washing machines and stainless steel surgical devices. Electropolishing is also commonly applied to the preparation of thin metal samples for transmission electron microscopy because electropolishing does not cause mechanical deformation of surface layers usually observed when mechanical polishing is used. Ultra high vacuum (UHV) components are typically electropolished in order to have a smoother surface for improved vacuum pressures, outgassing rates, and pumping speed.

Standards[edit]

ASME BPE Standards for Electropolishing Bioprocessing Equipment
SEMI F19, Electropolishing Specifications for Semiconductor Applications
ASTM B 912-02 (2008), Passivation of Stainless Steels Using Electropolishing
ASTM E1558, Standard Guide for Electrolytic Polishing of Metallographic Specimens

References[edit]

^ G.F. Vander Voort, ed., "Chemical and Electrolytic Polishing," ASM Handbook, Vol. 9: Metallography and Microstructures, ASM International, 2004, p 281-293, ISBN 978-0-87170-706-2.

External links[edit]

Electropolishing overview
Electropolishing Users Guide
Benefits of Electropolishing
Electropolishing Stainless Steel by Euro Inox

English Journal

Comparative study of the corrosion behavior of peripheral stents in an accelerated corrosion model: experimental in vitro study of 28 metallic vascular endoprostheses.

Paprottka KJ1, Paprottka PM, Reiser MF, Waggershauser T.
Diagnostic and interventional radiology (Ankara, Turkey).Diagn Interv Radiol.2015 Sep-Oct;21(5):403-9. doi: 10.5152/dir.2015.15062.
PURPOSE: Clinical cases of stent-fractures show that corrosion behavior might play a role in these fractures. Implanted in vivo, especially in combination with other implanted foreign materials, these metallic products are exposed to special conditions, which can cause a process of corrosion. Here,
PMID 26268301

Methods for atom probe analysis of microgradients in functionally graded cemented carbides.

Frykholm R1, Jansson B, Andrén HO.
Micron (Oxford, England : 1993).Micron.2002;33(7-8):639-46.
Methods to prepare needle-shaped specimens for atom probe field ion microscopy from near surface regions have been developed. The material used was a cemented carbide with a composition gradient towards the surface, but the method is equally applicable for other materials. The preparation technique
PMID 12475560

Electropolish finishing of stainless steel in pharmaceutical processing equipment.

Grimes TL, Fonner DE, Griffen JC, Rathbun LR.
Bulletin of the Parenteral Drug Association.Bull Parenter Drug Assoc.1975 Mar-Apr;29(2):64-73.
PMID 1120214

Japanese Journal

チオ尿素添加した研磨液におけるAu-Ag-Cu合金の電解研磨挙動

望月陽介,宮川和博,有泉直子 [他]
表面技術 = Journal of the Surface Finishing Society of Japan 65(4), 173-178, 2014-04
NAID 40020060144

低品位金合金用非シアン系電解研磨液の開発と研磨挙動の解明

望月陽介,有泉直子,宮川和博 [他],柴田正実
表面技術 = The journal of the Surface Finishing Society of Japan 63(8), 526-530, 2012-08-01
In this study, a non-cyanide electropolishing solution was prepared for low-grade gold alloy containing palladium (Pd). Electropolishing conducted with an existing non-cyanide electropolishing solutio …
NAID 10030992427