What Does
Electroplating Mean?
Electroplating is the process of coating a metal with a thin layer of another metal by electrolysis to improve the metal's corrosion resistance.
The metals most commonly used in plating are:
- Copper
- Nickel
- Gold
- Silver
- Chrome
- Zinc
- Tin
Electroplating is also known as electrodeposition and electroplated coating.
Corrosionpedia Explains Electroplating
The main purpose of electroplating is to improve:
- Appearance
- Protection against corrosion
- Special surface properties
- Engineering or mechanical properties
In the process of electroplating the anode is connected to the positive terminal, and the cathode (metal to be plated) is connected to the negative terminal. Both are immersed in a solution that contains an electrolyte and then connected to an external supply of direct current. When DC power is applied, the anode is oxidized—its metal atoms dissolve in the electrolyte solution. These dissolved metal ions are reduced at the cathode and form a coating. The current through the circuit is adjusted so that the rate at which the anode is dissolved equals the rate at which the cathode is plated.
Different metals can be coated using the electroplating process. Formulating the right electrolyte is important for the quality of plating.
Electrolytes used in this process include:
- Acids
- Bases
- Metal salts
- Molten salts
Properties of the electrolyte that must be considered when making a selection are:
- Corrosivity
- Resistance
- Brightness or reflectivity
- Hardness
- Mechanical strength
- Ductility
- Wear resistance