Lightweight Aluminum Alloys in Aerospace & Automotive
Aluminum alloys are known for their corrosion resistance, ductility, conductivity, appearance, strength, and most of all their light weight. In general, aluminum alloys are 1/3 the weight of carbon and stainless steels. So, when comparing the weight of aluminum to steel, it’s easy to calculate – you can just divide by three!
The lighter weight of aluminum makes it especially practical for applications where weight savings are critical, like aerospace and automotive.
In fact, when building their first airplane, the Wright Brothers knew that it was imperative to have a lightweight engine to power their plane. After having no luck finding a lightweight engine commercially available, the brothers decided to cast the engine block from an aluminum and copper alloy.
Their first successful flights at Kitty Hawk in December 1903 would change the world. If you want to learn more about flying, American ingenuity, and the brilliance and fearlessness of the Wright Brothers, read Pittsburgh’s own David McCullough’s book The Wright Brothers.
Lightweight Aluminum Alloys in Aerospace
Lightweight aluminum alloys have played a critical role in aviation ever since the Wright Brothers. The aerospace industry demands both high strength and high corrosion resistance. While the aluminum grades typical to the aerospace industry have high strength, the alloying of aluminum reduces its corrosion resistance. The aerospace industry gets around this by combining the lightweight aluminum alloys with alclad liners of pure aluminum that have high corrosion resistance.
7000 Series Aluminum
The aerospace industry relies most heavily on alloy 7075, which is one of the lightweight aluminum alloys with the highest strength. Like alloy 2024, its ratio of strength to weight is excellent and it is used in parts that will undergo high levels of stress. Alloy 7075 can be heat treated if needed.
2000 Series Aluminum
The aerospace industry mostly pulls from alloys 2011, 2014, and 2024. Alloy 2011, otherwise known as FMA, or Free Machining Alloy, is common in complex parts because of its high strength and excellent machining. Alloy 2014 has high strength and excellent machining due to the addition of copper and, because of its high corrosion resistance, is found in structural aerospace applications. Finally, alloy 2024 has both high strength and excellent fatigue resistance and is found in aerospace applications requiring a good ratio of strength to weight.
Lightweight Aluminum Alloys in Automotive
The automotive industry likewise realized that to improve fuel efficiency they needed lighter cars.
Corporate Average Fuel Economy Standards (CAFÉ Standards) established a goal of 50 miles per gallon for the average vehicle, which pushed more automakers to “light weight” their vehicles.
In a poll from 2015 conducted by DuPont, auto designers and engineers said that 33% of them would rely on aluminum to meet the new CAFÉ Standards.
The Aluminum Association believes that by 2025, 22% of sport utility vehicles, 24% of midsized sedans, and 75% of light trucks will use aluminum sheet for auto body panels (ABS).
Audi was the first car maker to mass produce aluminum body cars and Ford in recent years created quite a stir with aluminum body F150s.
Many series of aluminum alloys are found in the automotive industry. Here is a short list.
6000 Series Aluminum
The 6000 aluminum series are alloyed with silicon and magnesium. They are heat treatable and can be hardened after forming. Forecasters have predicted significant growth in the 6000 series aluminum market in the next 5-10 years. You’ll find 6000 series aluminum in the hoods, doors, trunks, and roofs of automobiles.
5000 Series Aluminum
The 5000 series of aluminum is alloyed with magnesium. They are non-heat treatable and show good corrosion resistance, good welding characteristics, and moderate-to-good strength. You’ll find the 5000 series of aluminum in truck trailers and non-critical automotive parts.
3000 Series Aluminum
The 3000 aluminum series are a general-purpose alloy of moderate strength. Alloyed with manganese, they exhibit good formability and workability and have a uniform appearance. You’ll find the 3000 series of aluminum in piping and heat insulators.
1000 Series Aluminum
The 1000 series of aluminum is pure aluminum. It is non-heat treatable and very malleable. It finds its way into heat insulators and license plates. Pure aluminum is the softest of the common alloys and used when deep drawing quality is demanded.
Aluminum Supply Chain Issues
Many of the domestic supply-side issues of late were caused by the aluminum mills moving more and more capacity to automotive alloys and away from common alloys like 3003 & 5052. That said, 3003 and 5052 do find their way into automobiles, 3003 in piping and 5052 in meter display panels, AT drums, air bag inflators, and covers. We previously wrote at length about the difference between 3003 and 5052.
How to Calculate the Weight of Lightweight Aluminum Alloys
To calculate the weight of aluminum sheet, multiply the gauge (thickness) x width x length x density of the alloy (pounds/cubic inch).
3003 has a density factor of .099 pounds per cubic inch and 5052 has a density factor of .097 pounds per cubic inch
A sheet of .063” x 60” x 120” 3003 would weigh .063 x 60 x 120 x .099 = 44.91 pounds
A sheet of .125” x 48” x 96” 5052 would weigh .125 x 48 x 96 x .097 = 55.87 pounds
If you have any questions, please do not hesitate to contact our non-ferrous team at firstname.lastname@example.org today. We’re happy to go over your aluminum needs with you.
Natalie Spira is Kloeckner's Marketing Communications Manager. Previously, she was the CEO and Founder of Fraction Marketing, a marketing agency catering to ecommerce startups. Natalie holds a MBA from Tel Aviv University with concentrations in entrepreneurship and marketing and a BA in English from UCLA.