Corrosion caused by galvanic action results from what?

Galvanic corrosion occurs when two different metals are in electrical contact in the presence of an electrolyte, leading to a galvanic cell formation. This electrochemical reaction can cause one of the metals to corrode faster than it would on its own due to the potential difference between the metals. The metal with a higher electrochemical potential acts as the anode, where oxidation and corrosion occur, while the metal with a lower potential acts as the cathode.

In the context of aircraft maintenance and construction, understanding galvanic corrosion is essential, as it can lead to integrity issues in structures where dissimilar metals are frequently used together, such as aluminum and steel components. Proper selection of materials, protective coatings, and insulation between these metals can mitigate the risk of such corrosion.

The other choices do not directly relate to the concept of galvanic action. Anodization and heat treatment deal more with surface treatment and material properties rather than the electrochemical interactions between metals, while a chemical spill typically refers to environmental contamination that affects material integrity but does not specifically induce galvanic corrosion.