Aluminum is unlike anything else on Earth. Also known as clay silver, this extraordinary metal has impacted every level of our society. From our airplanes to our tea kettles, aluminum is everywhere.

The best part? It's infinitely recyclable. Every time you crack open a soda can, 70% of that aluminum has been used more times than you can count! And every minute, our recycling plants melt down around 123,000 cans.

Here are some more facts about aluminum that'll blow you away.

Aluminum Fast Facts

• Aluminum is the most common metal on the Earth's crust, making up 8% of it
• It used to be more valuable than gold and silver
• Around 75% of the aluminum produced is still in use today
• The industry has decreased its carbon emissions by 40% since 1995
• The aluminum industry made $71 billion in 2021

A large portion of that industry was fueled by 6061 aluminum, an alloy mixed with magnesium and silicon that's become one of the most frequently used materials for construction, especially in marine and auto industries.

This article will explain the monumental impact 6061 aluminum has had on our global manufacturing industry and what makes it so popular.

But first, let's look at the history of aluminum and learn how incredible its influence really was on our global society – especially when we figured out how to transform it into alloys (a metal mixed with different metallic elements).

The Origin of Aluminum

Since pure aluminum isn't a naturally occurring metal, it took humans a long time to discover it. As an alloy, it's been around for ages. 

Paleontologists found Chinese armor from the third century consisting of 85% aluminum, while alum – an aluminum-based salt – has been used extensively and globally since ancient times.

An English chemist named Humphry Davy bestowed the name "alumium" -- later dubbed aluminum -- to the metal in 1809 after discovering you could create it in its pure form with electrolytic reduction using aluminum oxide. He never actually did it, but his theories burst open the door for the metal's impending popularity.

In 1825, Danish physicist Hans Christian Orsted got close by making an aluminum alloy. Still, it took 20 more years until German chemist Friedrich Woehler developed the first melted and then solidified pure aluminum spheres.

In 1856, French chemist and technologist Henri-Etienne Sainte-Claire Deville (what a name!) and his partners adapted aluminum production for the industrial space. 

Sainte-Claire Deville knew aluminum was perfect for industrial spaces because – and he quotes – "There is nothing harder than to make people use a new metal. Luxury items and ornaments cannot be the only sphere of its application. I hope the time will come when aluminum will serve to satisfy the daily needs."

His hopes were fulfilled shortly after when aluminum exploded in popularity. In the first 36 years after Sainte-Claire Deville implemented his new industrial process, almost half a million tons of aluminum were produced!

1886 came with two engineers – Paul Héroult, the French inventor, and Charles Hall, the American student – and their separate studies that led to a cost-effective electrolytic method for making aluminum. Unfortunately, it required a massive amount of energy to do. Héroult resorted to the Rhenish Falls in Switzerland for power, where aluminum production went from 40 tons in 1890 to 450 tons in 1895.

In the States, Charles Hall established the Pittsburgh Reduction Company in 1888, which also quickly improved its efficiency. Eventually, they built smelters near Niagara Falls to increase production capabilities, reorganized their company into the Aluminum Company of America, and succeeded incredibly. They're known today as Alcoa – the world's 8th largest manufacturer of aluminum.

The last major component of aluminum's industrial history is Austrian chemist Karl Josef Bayer's alumina production method by refining bauxite ore.

In 1888, Bayer perfected his refining process by–

1. Crushing, milling, and heating a mixture of sodium hydroxide and bauxite ore – a combination of aluminum oxides and other metals
2. Clarifying the solution and dissolving everything except alumina and silica, and 
3. Filtering the leftover material to convert the alumina to soluble sodium aluminates

Now, all aluminum is produced using the Hall-Héroult and Bayer methods. And they were put into effect quickly.

By 1899– 

• The first passenger boat was constructed using aluminum in Switzerland 
• The first torpedo boat was constructed in Scotland and broke record speeds
• J.P. Morgan's railroad company began constructing lightweight passenger train cars, and
• Mercedes' founder Karl Benz exhibited his first aluminum car in Berlin

But the most incredible feat of aluminum's potential came in 1903 when the Wright brothers flew the first human-crewed plane. The car engine used at first was too heavy, so they reconstructed it with aluminum components, lightening the plane and making it possible to fly. Today, 80% of aircraft parts are made of aluminum.

Aluminum has continued to be a key component in our history, like these major events–

• The Empire State Building was the first major structure built with aluminum both inside and outside in 1931
• The USSR sent aluminum to space for the first time in 1957, and it's never been sent by anyone without it since
• In 1967, Coca-Cola and Pepsi began producing their iconic drinks in aluminum cans

These are just a few ways aluminum has significantly impacted history. So it makes sense that by 2023, the demand for aluminum will reach 80 million tons per year.

What About Aluminum Alloys?

The first aluminum alloy was invented in 1885 by brothers Eugene and Alfred Cowles when they figured out how to thermally reduce a mixture of alumina, carbon, and copper into new material -- an aluminum-copper alloy. Two years later, co-inventor of the electrolytic method Paul Héroult invented an aluminum-bronze alloy. Because of his success, companies Aluminum Industrie Aktiengesellschaft and Société Électrométallurgique Française quickly opened alloy smelting plants using Héroult's methods.

In 1909, German metallurgist Alfred Wilm forever changed aluminum's impact on the world by developing the aluminum alloy Duralumin. It's mixed with magnesium, manganese, and copper – making the resulting metal much stronger, harder, and more elastic than pure aluminum. 

Duralumin quickly took over as the primary construction material for aircraft, most notably as the material used to build the Zeppelin airship. It's responsible for the majority of aircraft being constructed with it.

From then on, aluminum alloys became more advanced and arguably the most versatile metal on the market. 

The 7 Series of Aluminum Alloys

Currently, 7 major alloy types are used in aluminum production. The different types are organized into 7 series. Within each series is an alloy combination ID'd by a number that begins with the series it belongs to. The numbers look like this–

1xxx, 2xxx, 3xxx, 4xxx, 5xxx, 6xxx, 7xxx

Here's what classifies each aluminum alloy into its series.

1000 Series

This series is the purest form of aluminum at 99% purity, and it's highly useful in manufacturing because it's–

• Extremely resistant to corrosion
• The most weldable of any aluminum series
• Very thermally and electrically conductive, and
• Soft, meaning it's highly workable and ductile

2000 Series

The 2000 series are copper alloys – usually around 2% to 10% worth. Aircraft and aerospace industries use it frequently because it increases strength, machinability, and hardness.

However, creating an aluminum-copper alloy reduces the original metal's resistance to corrosion and ductility. It's also one of the hardest to weld because it's prone to cracking upon solidification.

3000 Series

This group consists of aluminum-manganese alloys used for their incredible strength, formability, and resistance to chemical agents.

You'll see these alloys used for things like–

• Food processing
• Chemical processing
• Siding
• Cooking utensils
• Roofs
• Gutters
• Vehicle trim, and
• Heat exchangers

4000 Series

Next is the 4000 series, used for welding filler material, pistons, and brazing products – to name a few. It's made with silicon to create a much "meltier" metal with high-temperature performance and good wear resistance.

5000 Series 

Magnesium is the alloying element in the 5000 aluminum series – making the resulting metal extremely resistant to corrosion (especially in marine environments), moderately strong, and weldable.

The downside of 5000 series aluminum is its intolerance of extreme temperatures. They don't do well in really cold environments and can experience stress corrosion if it's too hot.

However, you'll find 5000 series aluminum used everywhere in marine and architectural sectors and things like zippers, conductors, wires, signage, and screens.

6000 Series

The 6000 series of aluminum contains our article's muse – as well as magnesium and silicon. This series of aluminum alloys is extremely popular because it's affordable and readily available. 

6000 series aluminum is also–

• Resistant to corrosion
• Formable
• Machinable
• Weldable
• Moderately strong, and
• Durable

These are primarily used for extrusions and make up the majority of aluminum tonnage produced for them. You'll also find them in structural and architectural components. 

We'll talk about 6061 aluminum specifically just ahead, but first, let's quickly learn about the last series of aluminum alloys.

7000 Series

The last series contains zinc and is used for high-performance applications because it's stronger than other aluminum alloys. They're used mainly in military and aircraft sectors in structural components and wires, rods, bars, tubing, and more.

The downside of these aluminum-zinc alloys is their low corrosion resistance level, but many manufacturers paint, prime, or chemically seal the metal to increase resistance.

What's So Special About 6061 Aluminum?

Now that we've covered the 7 alloy series, let's focus on why 6061 aluminum is often considered the most versatile.

6061 aluminum first went by Alloys 61s when it was developed in 1953 and has become the most popular choice of the 6000 series and one of the most popular of all the series.

This alloy's chemical composition consists of these ranges of elements–

The exact percentages will vary depending on the product you’re making with the alloy because each element has its own benefits.

Here’s an overview of how each of these added elements transform aluminum into the outstanding 6061 alloy.

Manufacturers will create 6061 with different amounts of these additives according to their needs. Ultimately, their goal is to add specific amounts of these elements to manipulate some of the many advantages of 6061 aluminum and make a specific product. 

Using these additives, manufacturers will reduce or improve the effects of these 6061's popular advantages–

• Low cost
• High thermal conductivity
• Versatility
• Medium strength
• Lightweight
• Heat-treatable
• Weldability
• Durability
• Brazeability, and
• High resistance to air or water corrosion

When certain elements are added to 6061, its power as a versatile material is flexed, which led to its nickname, "structural aluminum."

Structural Aluminum

6061 is also called structural aluminum because it's used in many construction products. You'll see 6061 to engineer and construct things like–

• Boats
• Camera lenses
• Furniture
• Fasteners
• Scuba tanks
• Automotive parts
• Vehicle frames and components
• Welded assemblies
• Piping
• Construction products, and
• Electrical products

It would be impractical to list every use of 6061 because there are simply too many. Its versatility and popularity are only rivaled by 7075 aluminum, often compared to each other in various applications.

Let's look at their differences to see when 6061 aluminum is the best choice for production.

6061 vs. 7075 Aluminum

7075 is also called structural aluminum because it's extraordinarily strong. With zinc as its main additive, 7075 aluminum is top-notch when it comes to quality and durability.

When choosing between 7075 and 6061 aluminum, you must consider factors like corrosion resistance, hardness, and conductivity. Different jobs have different needs.

Regarding hardness, both alloys are capable of withstanding pressure, but 7075 is harder than 6061.

For corrosion resistance, 6061 is superior and can outlast 7075 because of its lower copper content.

In terms of electrical conductivity, both have low electrical resistivity, but 6061 has the lowest of the series, making it a better conductor than 7075. 6061 also outperforms in thermal conductivity.

Of course, there are a ton of other factors to consider between the two, but generally, you'll want to choose 6061 aluminum when you–

• Have a concern about corrosion
• Want to save money, and
• Require a lot of machining and welding

7075 aluminum, on the other hand, is best when–

• A high strength-to-weight ratio is vital
• You aren't worried much about the cost
• There will be high heat exposure, and
• Friction will be heavily involved

The Future of Aluminum

The future of aluminum is bright. In January 2022, Aluminum Association CEO Charles Johnson said–

"We are seeing strong demand and truly unprecedented levels of investment in the US aluminum industry today. America is one of the best places in the world to make aluminum and our industry is putting its money where its mouth is to ensure a strong, vibrant domestic industry for years to come."

His observation comes after aluminum demand rose from its slump due to the COVID-19 pandemic. From June 2020 to 2021, the demand for aluminum increased by 6.6%. Domestic producer shipments also increased – this time by 13% – because of the market's shift to eco-friendly packaging and aluminum's infinite recyclability.

The aluminum can is the most recycled item in our country. More than half of America's aluminum is recycled every year – and it's becoming easier to reuse over and over again.

95% less energy is needed to recycle aluminum than produce it, so it's a significant priority for manufacturers to reduce costs by reusing material as much as possible.

In May of 2022, Kentucky and Novelis – an aluminum company that recycles more of it than anywhere in the world – broke ground on a massive $365 million recycling plant that will take on 240,000 tons of automotive aluminum every day. Novelis released a statement predicting a 1 million ton reduction in carbon emissions every year and their growth into other areas of North America to reduce emissions and create jobs everywhere.

Wrapping Up

If you want to learn more about engineering, manufacturing, and technology, we've got you! At EMS, we geek out over this stuff.

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