Why is Aluminum A Preferred Metal Choice in Aerospace Industry?

According to the Aluminum Association, the history of air and space flight parallels the history of aluminum alloy advancement and production. Next to steel, aluminum sheet is the most commonly used and commercially available metal. Its soft, ductile texture has been fortified with a number of different metals to create alloys that exhibit highly useful qualities that have served the aerospace industry for over 100 years.

First Flight

Aluminum's lightweight and high strength-to-weight ratio make it a good choice for aircraft, which is probably why the Wright brothers chose it to build parts of the engine used for their ground-breaking successful flight back in 1903.

Though the first primitive airplanes were made of lightweight wood, the downside of wood is that it's susceptible to rot. For that reason – and as it became more readily available – aluminum became the go-to construction material for aircraft by the beginning of WWI.

Rise of the Aluminum Industry

A generation later during WWII, the U.S. built almost 300,000 aircraft, both for itself and our allies – with the help of a flourishing aluminum industry.

After the war, the beginning of spaceflight was achieved with the help of aluminum. For instance, the Titan family of rockets used to launch the manned Gemini craft into orbit in the 1960s was made of aluminum.

In use from the 1960s to the 1990s, the Lockheed SR-71 Blackbird reconnaissance plane – one of the fastest aircraft ever built – had an internal aluminum frame
From 1969 to 2003, aluminum-skinned supersonic Concorde passenger jets flew across the Atlantic at twice the speed of sound.
The Space Shuttle Discovery, which flew astronauts around the Earth from 1984-2011, had a backbone of aluminum alloy plate and had an external fuel tank made of aluminum. Its solid booster rockets were powered by aluminum metal mixed with solid ammonium perchlorate.

Modern Age of Aluminum

Still one of the world's most popular jet planes, the Boeing 737 is approximately 80 percent aluminum, with different alloys used for different parts of the aircraft. For example, the fuselage skin, slats, and flaps are made of Aluminum 2024 (alloy of aluminum and copper), chosen for its good fatigue performance, fracture toughness, and slow crack propagation rate. Meanwhile, the wing upper skin, spars & beams are made of Aluminum 7075 (aluminum alloyed with zinc, magnesium, and copper), known for its high compressive strength-to-weight ratio.
The primary structure of NASA's Orion spacecraft, the next-generation space exploration vehicle which will someday transport people to Mars, is constructed of an aluminum-lithium alloy.

Aluminum: The Cost-Effective Solution

Though not as strong as titanium or carbon-alloy steel, and heavier than composites, aluminum costs less and has a good balance of strength and low weight that make it a great fit for aircraft. When alloyed with other materials, aluminum exhibits many additional properties beneficial to flight, such as stress corrosion cracking resistance and high tensile strength. Aluminum sheet & plate is as strong as steel at a fraction of the weight. Aluminum sheet & plate is also highly resistant to corrosion, which adds to its overall value. As manufacturing technologies advance, aluminum is sure to stay in the forefront of air and space craft for the foreseeable future.
For more information about aluminum metal supplies, contact Industrial Metal Supply today.