Composite materials have become increasingly common in the aerospace industry. Modern airplanes like the Boeing 787 are often comprised of at least 50% composite materials. Consisting of reinforcing fibers mixed with a polymer matrix, they offer a superior strength-to-weight ratio. Airplanes, however, still contain other materials, such as aerospace-grade aluminum. Here are six facts about aerospace-grade aluminum.
#1) Not the Same as Aluminum
Aerospace-grade aluminum isn’t the same as plain aluminum. It’s essentially a specialized alloy consisting of aluminum with other elements. Plain aluminum is susceptible to stress fatigue and oxidation. Therefore, other elements like copper, zinc, magnesium and lithium are added to it. The end result is aerospace-grade aluminum, which is typically stronger and more durable than plain aluminum.
#2) Strong and Lightweight
Aerospace-grade aluminum is strong and lightweight. Plain aluminum is known for being relatively weak, with a tensile strength of around 13,000 pounds per square inch (PSI). Aerospace-grade aluminum, on the other hand, has a tensile strength of around 45,000 to 90,000 PSI — sometimes even higher. Even with its high tensile strength, aerospace-grade aluminum is lightweight, making it ideal for use in airplanes and other aircraft.
#3) Available in Different Types
While they all consist of aluminum and alloying elements, not all aerospace-grade aluminum is the same. Common types of aerospace-grade aluminum include aluminum 7075, aluminum 7068 and aluminum 2024. Each type has a different composition of alloying elements, resulting in different physical characteristics. Aluminum 7068, for instance, has a very high tensile strength, whereas aluminum 2024 has a better strength-to-weight ratio.
#4) Used For Many Aircraft Parts
Many aircraft parts are made of aerospace-grade aluminum. Fuselage skins, for instance, are often made of this strong and lightweight aluminum alloy. The wings are also regularly made of aerospace-grade aluminum. Even aircraft frames and landing gear systems are made of aerospace-grade aluminum.
#5) Excellent Resistant to Corrosion
In addition to being strong and lightweight, aerospace-grade aluminum offers excellent resistance to corrosion. Aluminum itself develops a natural layer of oxide when exposed to oxygen, which helps to preserve and protect it from oxidative damage like corrosion. Aerospace-grade aluminum, though, contains other alloying elements to further enhance its resistance to corrosion.
#6) Recyclable
Aerospace-grade aluminum is recyclable. When an airplane reaches the end of its usable life, it’s typically broken down for parts. Parts that can’t be reused or repurposed may be recycled, including those made of aerospace-grade aluminum. Recycling saves as much as 95% of the energy needed to produce new aluminum materials.
