There exists a method called cathodic protection to protect the material from corrosion. The method involves connecting an external anode to the material and passing eclectic DC current. As a result, the entire material becomes cathodic and no corrosion takes place. There are two options in making the anode, the one is to make galvanic anode also called sacrificial anode, while the other is in which current from external DC source is passed.
For the making of sacrificial anode, one of the three elements are used, namely zinc, aluminum and magnesium. These metals are highly active which protect the less active metals from corroding.The sacrificial metal has more negative electrochemical potential than the other element. So instead of the material corroding, the anode begins to corrode, hence the name sacrificial anode.
The uses of sacrificial anode
- The sacrificial anodes are used to protect the ship hulls
- They protect water heaters
- The conserve pipelines and distribution systems
- Besides, they protect above and underground tanks and refineries
- The sacrificial anodes alos protect marine rcc structures and concrete floors