What Does Electropolishing Mean?
Electropolishing is an electrochemical process by which surface material is removed by anodic dissolution under optimum conditions of current density and temperature. It is often described as the reverse of electroplating.
Electropolishing is used to polish, passivate, and deburr metal parts. It may be used in place of abrasive fine polishing in microstructural preparation. Electropolishing produces a combination of properties which can be achieved by no other method of surface finishing. The corrosion resistance of electropolished stainless steel exceeds that of standard passivation processes.
It is also known as electrochemical polishing or electrolytic polishing (especially in the metallography field).
Corrosionpedia Explains Electropolishing
Electropolishing is an electrochemical process that removes a controlled amount of material from the surface of stainless steel and other metal alloys. It is the process of smoothing metal surfaces to make them highly corrosion resistant. This is a method of producing simultaneous brightening, smoothing, deburring, cleaning, and passivation on stainless steels or other metal alloys.
Due to its simplicity, it can be applied to objects of complex shape. Electropolishing has many applications in the metal finishing industry. It is used on:
- Stainless steel automotive, appliance, and household products for decorative finishes
- Stainless steel drums for washing machines
- Stainless steel surgical devices, preparation of thin metal samples for transmission electron microscopy
- Equipment for the manufacture and packaging of food, beverage and pharmaceutical products
- Products requiring smooth, low-friction operation
- Ultra high vacuum (UHV) components for a smoother surface, improved vacuum pressures, outgassing rates and pumping speed
Electropolishing is accomplished by creating an electrochemical cell in which the material to be polished is charged anodically. A cathode is formed to mirror the geometry of the work surface and the two are submerged in a heated electrolyte bath. When a DC current is applied, the electrical charge forces metal ions to be dissolved from the stainless steel work surface. After the electropolishing treatment, the work piece is passed through a series of steps to neutralize, rinse, clean and dry the surfaces.
Benefits of electropolishing include:
- Increased resistance to corrosion
- Improved surface finish
- Reduced product adhesion & ease of cleaning
- Attractive appearance