sacrificial anode
Noun
Meaning
sacrificial anode (plural sacrificial anodes)
(manufacturing) A piece of corrodible metal, attached to a metallic surface to be protected, that is preferentially consumed by electrolytic action
Synonyms
Examples
The engine's casing is mostly missing, having acted as a sacrificial anode in its time underwater but the internals are remarkably preserved.
The sacrificial anode must be made from something with a more negative electrode potential than the iron or steel, commonly zinc, aluminium, or magnesium.
In its simplest form, it is achieved by attaching a sacrificial anode, thereby making the iron or steel the cathode in the cell formed.
These approaches rely on the aluminium and zinc oxides reprotecting a once-scratched surface, rather than oxidizing as a sacrificial anode as in traditional galvanized coatings.