What may occur if the surface of a cladded metal is scratched beyond the protective layer thickness?

• A. Delamination
• B. Pitting
• C. Corrosion may start
• D. Wear

Answer: (C)

Protective cladding is the barrier that keeps moisture, oxygen, and other corrosives away from the base metal. If you scratch through that layer, the underlying metal is exposed to the environment, and electrochemical corrosion can begin there. The exposed area becomes the starting point for corrosion under typical aircraft conditions (moisture, salts, humidity), and a corrosion cell can form at that spot. Wear is a mechanical issue, and delamination would require the cladding to separate from the substrate, which isn’t the immediate result of simply breaching the layer. Pitting can occur as a form of corrosion, but the initial and most direct consequence of breaking the barrier is that corrosion may start.