Metal finishing is a type of surface finishing that can be defined as the deposition of a metallic coating onto a product either to enhance performance, function or aesthetic qualities while providing overall added value. While it’s not obvious on a daily basis, many objects have been subjected to metal finishing for use in our normal lives. These include parts in a car, aircraft, fencing, medical and dental devices, industrial machinery or even beautiful pieces of art. The term finishing is based on the fact that it’s normally the last step of the manufacturing process (save for any heat treatment).
Types of Metal Finishing
In the world of metal finishing, there are countless techniques, methods, and processes to achieve similar objectives. A few of the more notable ones include:
- Electroplating – An electrodeposition plating process method which utilizes electrowinning principles by submerging the item to be plated as a cathode and the desired metal for its coating as the anode.
- Electropolishing – A polishing method often considered reverse electroplating, where the parts are the anode and the passing current will result in dissolution of the part’s top layer removing flaws from the surface into the electrolytic solution.
- Electroless Plating – A plating method which does not use external electricity, but instead uses several concurrent electroless reactions in an aqueous solution.
- Metal Etching – A chemical process where lines are engraved into a metal part that is typically covered with a specialized acid-resistant coating. The engraved lines expose the surface leaving those areas open to defined etching when submerged into an acid bath.