When two metals having differing electrode potentials are in contact with each other in the presence of an electrolyte, one metal acts as a cathode, whereas the other acts as an anode. This leads to an electrochemical reaction; as a result, the anode is dissolved into the electrolyte. This electrochemical process is called galvanic corrosion of metals. Galvanic corrosion can only occur when an electric conducting path connects the metals and when an electrolyte that can offer a channel for the migration of ions is present.
Methods to prevent galvanic corrosion.
- The electroplating process of the metal to form a thin layer of inert metal on it can also help reduce galvanic corrosion.
- Placement of Electrical Insulation between the two Metals to stop the flow of electrons between them and prevent galvanic coupling.
- Usage of a Galvanic isolator can be two series-semiconductor diodes placed in parallel with two diodes conducting in the opposite direction.