Definition - What does Aluminium Anode mean?
An aluminum anode is a galvanic anode and a major component of a galvanic cathodic protection system, which is used to prevent corrosion of buried or submerged metal structures such as pipelines, tanks or other related equipment. They are also classified as sacrificial anodes, which are intended to sacrifice themselves to the corrosion process, thereby leaving the rest of the system relatively corrosion-free.
Corrosionpedia explains Aluminium Anode
Normally, cathodic protection (CP) can be produced by sacrificial or galvanic anodes made from aluminum or an impressed current system. Galvanic CP can be produced by a galvanic or sacrificial system when limited amounts of current are needed, soil resistivity is low (normally less than 5,000 ohm/cm) and electric power is limited or not available.
In addition to aluminum anodes, these galvanic or sacrificial anodes are also made in various shapes using alloys of zinc and magnesium.
Cathodic protection using aluminum anodes is accomplished by coupling the metal structure to be protected with a more active metal, such as aluminum. This produces a galvanic cell in which the active metal works as an anode and provides a flux of electrons to the structure, which then becomes the cathode. The cathode is protected while the anode is progressively destroyed, and therefore is called a sacrificial anode. Sacrificial anode systems depend on the differences in corrosion potential that are established by the corrosion reactions that occur on different metals or alloys.
The advantages of aluminum anodes in galvanic cathodic protection systems include:
- Guaranteeing the protection of reinforcement rods against corrosion.
- Preventing corrosion on older structures with no signs of deterioration.
- Increasing durability of new structures.
- Minimal maintenance requirements.
- An alternative to using a zinc coating/plating to protect metals and existing structures against corrosion.