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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/06/26 06:30:11」(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

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; 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.^{[citation needed]}

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

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

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

Benefits of electropolishing (stainless steel)

Removes iron from the surface and enhances the chromium/nickel content providing the most superior form of passivation for stainless steel.
Provides a clean and smooth surface that is easier to sterilize.
Polishes areas inaccessible by other polishing methods.
Improves the surface finish by leveling micro-peaks and valleys.
Removes a small amount of material from the surface of the parts, also removing small burrs.
Can be used to reduce the size of some parts when necessary.
Results are seen by many as aesthetically pleasing.^[2]

References

^ 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.
^ Stainless Steel Electropolishing. Arrow Cryogenics http://www.arrowcryogenics.com/stainless-steel-electropolishing.htm. Retrieved 28 February 2014. Missing or empty |title= (help)

External links

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

English Journal

Molecular motion and ion diffusion in choline chloride based deep eutectic solvents studied by 1H pulsed field gradient NMR spectroscopy.

D'Agostino C, Harris RC, Abbott AP, Gladden LF, Mantle MD.SourceDepartment of Chemical Engineering & Biotechnology, University of Cambridge, Pembroke Street, Cambridge, CB2 3RA, UK.
Physical chemistry chemical physics : PCCP.Phys Chem Chem Phys.2011 Dec 28;13(48):21383-91. Epub 2011 Oct 28.
Deep Eutectic Solvents (DESs) are a novel class of solvents with potential industrial applications in separation processes, chemical reactions, metal recovery and metal finishing processes such as electrodeposition and electropolishing. Macroscopic physical properties such as viscosity, conductivity
PMID 22033601

Nanosized controlled surface pretreatment of biometallic alloy 316L stainless steel.

Abdel-Fattah TM, Loftis D, Mahapatro A.SourceApplied Research Center, Jefferson National Laboratory, Newport News, Virginia, VA 23606, USA.
Journal of biomedical nanotechnology.J Biomed Nanotechnol.2011 Dec;7(6):794-800.
Stainless steel (AISI 316L) is a medical grade stainless steel alloy used extensively in medical devices and in the biomedical field. 316L stainless steel was successfully electropolished via an ecologically friendly and biocompatible ionic liquid (IL) medium based on Vitamin B4 (NB4) and resulting
PMID 22416578

Japanese Journal

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,柴田正実
表面技術 = The journal of the Surface Finishing Society of Japan 63(8), 526-530, 2012-08-01
NAID 10030992427

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]
表面技術 63(8), 526-530, 2012-08-00
NAID 40019405814

Effect of Electric Potential and Mechanical Force on Copper Electro-Chemical Mechanical Planarization

Chen Sheng-Wen,Kung Te-Ming,Liu Chuan-Pu [他],Chang Shih-Chieh,Cheng Yi-Lung,Wang Ying-Lang
Jpn J Appl Phys 51(3), 036504-036504-7, 2012-03-25
… In chemical etching, CMP, electropolishing, and ECMP processes, the Cu removal rate is mainly affected by the interplay between electric potential and mechanical force. …
NAID 150000104960