Sacrificial anodes

Definition

Sacrificial anodes are highly active metals used to prevent a less active material surface from corroding. They work by being intentionally corroded in place of the protected metal.

5 Must Know Facts For Your Next Test

1. Sacrificial anodes are commonly made from zinc, magnesium, or aluminum.
2. The process of using sacrificial anodes is known as cathodic protection.
3. In galvanic corrosion, the sacrificial anode acts as the anode and corrodes instead of the protected metal.
4. Sacrificial anodes are often used in marine environments to protect ship hulls and offshore structures.
5. The effectiveness of a sacrificial anode depends on its position relative to the protected metal and the electrolyte.

Review Questions

• What is the primary function of a sacrificial anode?
• Which metals are typically used as sacrificial anodes?
• How does a sacrificial anode protect another metal from corrosion?

Related terms

Cathodic Protection: A technique used to control the corrosion of a metal surface by making it the cathode of an electrochemical cell.

Galvanic Corrosion: Corrosion that occurs when two dissimilar metals are in electrical contact in a corrosive environment, leading to accelerated corrosion of one metal.

Electrolyte: A substance containing free ions that make it electrically conductive; it plays a crucial role in electrochemical reactions.