1889
Hall-Héroult Process
Charles Martin Hall (1863–1914), Paul Héroult (1863–1914)
Think about how common aluminum is today, and how important it is to engineers as a structural material. Out in the garage we find aluminum in bicycle frames and rims, and some cars now have aluminum parts to lighten the vehicle. But the place where we see aluminum the most is in aircraft. Every airliner that flew up until 2010 was made primarily out of aluminum. The same goes for just about every rocket and spacecraft, including the International Space Station. The Boeing 787 is the first commercial airliner to be made primarily of carbon fiber instead of aluminum.
The reason aluminum is so popular, especially in airplanes, is because it is relatively inexpensive, easy to work with, durable, and light. A piece of aluminum that has the same strength as a steel piece might weigh half as much. If you take a cube of aluminum that weighs 1 pound, the same size cube of steel weighs about 2.8 pounds.
If you were to double the weight of most airplanes by using steel instead of aluminum, the airplane would not be able to fly, or it could only fly with zero payload. Aluminum makes it possible for engineers to design airplanes that can get off the ground. Before aluminum became common, airplanes were made of wood and cloth.
Aluminum was first purified in 1825. But it was extremely expensive—roughly equivalent to gold in price. In 1889 a new patent for a system called the Hall-Héroult process, which was developed by American chemist Charles Martin Hall and Frenchman Paul Héroult, demonstrated how to make inexpensive aluminum, and the rest is history. Once aluminum became inexpensive, and then abundant, its use exploded. Today, over 30 million tons of aluminum are used every year.
Just about every vehicle is better when it is lighter, so engineers use aluminum everywhere they can. With new mass production techniques, aluminum is replacing steel in more and more cars.
SEE ALSO Bessemer Process (1855), Carbon Fiber (1879), Boeing 747 Jumbo Jet (1968), The Concorde (1976), Space Shuttle Orbiter (1981), Apache Helicopter (1986), International Space Station (1998).
The interior of a bomber, created with aluminum.