Electropolishing process and controlled anodic dissolution of metals overview and explaination of the benefits of electropolished components including surface smoothness, corrosion resistance and Bio and Hemocompatibility Improvement.


The process of electropolishing is the controlled anodic dissolution of metals (alloys, intermetallic compounds, etc.) which remarkably improves surface properties of metals.

To establish optimum conditions for electropolishing a particular metal or alloy, a V-I curve is plotted and a plateau of current densities is established. The current densities plateau mainly exists just below the oxygen evolution regime. However, for many metals, alloys, etc., the best electropolishing results are obtained beyond this plateau under oxygen evolution conditions. The best example is most often industrially used electropolishing process for electropolishing austenitic stainless steels, which are carried out under oxygen evolution regime

ELECTROBRIGHT takes great care in ensuring that each component treated by electropolishing maintains its integrity.

Electropolishing Benefits:

Surface Leveling

According to the Theory of Jacquet (viscous film theory), the dissolution products accumulate near the anode (electropolished surface) and form a visous layer that increases the resistance of the system and limits the current. This viscous layer over peaks is much thinner than over depressions. Consequently, the current density over peaks is higher than over depressions, which results in the fact that peaks dissolved faster and the leveling effect is observed.

Corrosion Resistance

The remarkable improvement in corrosion resistance of electropolished surfaces are caused by several interconnected events occurring during the electropolishing process:
  1. Removal of deformed Beilby layer, which consists of inclusion of martensitic phase (Fig. 1), foreign material, preexisting oxides, etc., created by forming, machining, mechanical polishing, etc.
  2. Creating new corrosion resistant outer layer that is enriched in chromium oxide due to selective dissolution of ferromagnetic elements (Fe, Ni)
  3. Improving the surface smoothness by dissolving the surface picks preferentially to the surface depression
  4. Equipotentializing gain boundaries


Improved cleanability of electropolished surfaces is the result of two interconnecting parameters:
  1. Improvement of surface smoothness and profile
  2. Lowering the water contact angle (making the surface more wettable). Standard electropolishing reduces water contact angle about 12%

Bacterial Attachment and Early Biofilm Formation Reducibility

Many studies have been done by the US Department of Agriculture (J.W. Arnold et al., ‘”Surface Finishes on Stainless Steel Reduce Bacterial Attachment and Early Biofilm Formation: Scanning Electron and Atomic Force Microscopy Study) indicates that electropolished surfaces are less susceptible to bacterial attachment and early biofilm formation. This feature of electropolishing is of great importance for pharmaceutical, biotech, food and beverage industries.

Bio and Hemocompatibility Improvement

Electropolishing process is widely used for treatment of body implants and medical devices. The study by Tepe G. at.al., “Thrombogenicity of various endovascular stents types an in vitro evaluation” J Vasc Inter Radiol. 2002 Oct, 13 (10): 1029-35 shown that electropolishing clearly reduced the thrombogenicity of the stents.

Click Here to Request a Quote
Electropolishing Special & Exotic Metals
Electropolishing Process Results on Stainless Steel

Figure 1
Figure 1a
Stainless Steel Metal Surface Before Electropolishing Process
Figure 1b
Stainless Steel Metal Surface After Electropolishing Process

Figure 1 - X-ray diffraction patterns of 316LSS

Figure 1a: Mechanically polished
Figure 1b: Electropolished

Austenite phase

Martensite phases

Martensite phase has been removed by electropolishing process.

Sharpe Metal Finish Before Electropolishing
Sharp profile before electropolishing
Rounded Metal Finish After Electropolishing
Rounded profile after electropolishing
142 W. Main St .
Macungie, PA 18062
Phone: 610-967-5800
Fax: 610-967-5800