Cathodic coating involves coating a metal that is cathodic with respect to the substrate in the electrochemical cell.
The purpose of this coating is to protect the substrate from corrosion. In corrosive environments, if the cathodic coating fails to protect the substrate, it will accelerate substrate corrosion.
Cathodic coating is also known as electrophoretic deposition (EPD), e-coating, electrocoating, cathodic electrodeposition, electrocoating, anodic electrodeposition, and electrocoating.
The cathodic coating process involves immersing a part in a vessel containing a coating bath or solution and using electrodes to apply a direct current through the cathodic electrodeposition bath. Typically a voltage of 25-400 volts is used in electroplating. The object to be coated is one of the electrodes (the cathode), and a set of counter electrodes is used to complete the circuit.
After deposition, rinse the object to remove undeposited bath fluid. The coating finally undergoes a curing process in which the porosity is reduced and the coating material is cross-linked. This makes the surface smooth and continuous.
Cathodic coatings are used in the following areas:
hybrid electric vehicle
portable electronic device
medical equipment
Space and defense related equipment
