The Electropolishing Process | An Introduction

Electropolishing is a process used to make metal surface smooth and shiny through an electro-chemical reaction.  The metalwork is submerged in an electrolytic solution and fed an electric charge.  The resulting reaction dissolves a small amount (typically an amount measured in microns) of material on the surface, leaving a bright, smooth finish.

Unlike mechanical finishing, which uses an abrasive to remove surface metal from a work piece, electropolishing results in a smaller change in the item’s dimensions and carries a much smaller risk of damage to the piece.

The Electropolishing Process In More Detail

The electropolishing process often begins with precise measurements of the work piece to help ensure that the dimensions and values of the metal is not altered too substantially – a step that is critical for many manufactured parts that require exacting specifications.  Once these measurements are properly taken and documented, the first step of the electropolishing process can begin.

• Step One – The metal component is first submerged in a bath of electrolytic chemicals.  These chemicals are usually a highly viscous and acidic mix of sulfuric and phosphoric acid which are highly ionized. That is to say that the liquid contains a high number of ions that can be quickly decayed by an electric current. The part is then connected to the positive terminal of an electricity source.

• Step Two – The second step of the electropolishing process introduces a negatively charged cathode to the electrolyte solution with great care taken to not allow contact of the cathode and the positively charged part.
• Step Three – The final step of the electropolishing process activates the electrical current, which polarizes the electrolyte solution.  Material of the positively charged work piece are dissolved away from the surface and attracted magnetically to the negatively charged cathode around it.

Throughout the entire process the surface of the metal is protected by a layer of oxygen which prevents a runaway reaction and protects the surface and any delicate etchings in the metal from being damaged.

After the electrical charge is applied for a set amount of time the item can be removed from the electrolyte bath and rinsed to remove any chemicals that may further oxidize or damage the piece.  The final result of the electropolishing process is a much smoother, highly polished work piece.

Applications Of The Electropolishing Process

Because it allows for total immersion and microscopic accuracy within 1/10,000 of an inch, the electropolishing process is frequently used to finish complex metal structures, such as the interior of a washing machine drum with a multitude of holes and curves.  Finishing an item such this by other means would be very delicate and time-consuming work.

Polishing by other means can also damage the item or alter its dimensions.  For precision instruments, such as surgical tools, this can be particularly harmful.

The electropolishing process also helps to passivate the surface of a metal component, making it much more resistant to rust and corrosion.  The smoother surface is also easier to clean and sanitize for use.  These two effects of the electropolishing process make it perfect for many industries, including:

• Aerospace Manufacturers
• Water Craft Manufacturers
• Plumbing & Electrical Manufacturers
• Sheet Metal Manufacturers
• Medical Equipment Manufacturers
• Pharmacy Equipment Manufacturers
• Food & Beverage Equipment Manufacturers
• And Many Others

Benefits Of The Electropolishing Process

Many benefits of the electropolishing process are mentioned above.  Some more of the many benefits of electropolishing include:

• A finer, smoother, more reflective appearance for esthetic purposes.
• Increased life and total parts production in industrial machinery.
• A faster, streamlined means of finishing metal components over mechanical finishing.
• Can be used on nearly any metal with low silicon, lead, and sulfur contents.

Central Electropolishing Co. Inc.’s Electropolishing Process

Central Electropolishing Company uses the most advanced techniques to ensure the safest, highest quality electropolishing process in the country.  With more than 30 years of experience in the field of electropolishing and a vast wealth of satisfied customers behind us, we know the process like the back of our hand – and we’re ready to prove it to you.

Contact us today to learn more about Central Electropolishing Co.’s Advanced Electropolishing Process.