Why are clad aluminum alloys used in aircraft?

Clad aluminum alloys are primarily used in aircraft due to their enhanced corrosion resistance compared to uncoated aluminum alloys. In the aerospace industry, where aircraft are exposed to diverse environmental conditions, including moisture and various chemicals, the susceptibility to corrosion is a significant concern. Cladding involves the application of a thin layer of a more corrosion-resistant alloy (often aluminum-lithium) over the core alloy, which provides excellent protection against oxidation and corrosion.

This protective layer helps maintain the mechanical properties of the core alloy while significantly reducing the tendency to corrode, thereby extending the lifespan of the aircraft components. This corrosion resistance is particularly vital as it contributes to safety, maintenance costs, and overall structural integrity.

While other options mention strength, heat treatment, or heat resistance, they do not accurately capture the primary advantage of clad aluminum alloys in aircraft applications, which is their enhanced corrosion resistance.