A One-Stop Guide to Automotive Aluminum

Automotive aluminum has been around since aluminum was first produced. At the time, it was prohibitively expensive to use as an auto material en masse. But as aluminum became more affordable, and more and more aluminum alloys have been engineered to meet the specific needs of the automotive industry, it has become today’s fastest growing automotive manufacturing material.

The range of applications for aluminum in cars evidences the beautiful versatility of the material. It’s being used for doors, hoods, trunks, electrical wiring, transmissions, air conditioner condensers and tubes, engine parts including pistons, radiators, and cylinders, display paneling, crossmembers, brake systems, and the list goes on!

Aside from the basic properties of aluminum that make such widespread application possible, there are two key advantages of aluminum causing modern car makers to prefer it. The first is that it improves fuel economy, which is an easy sell for consumers who’ll save money by spending less on gas. And the second reason is that choosing aluminum for auto manufacturing can reduce CO2 emissions because of its lower weight.

Reasons Why Aluminum is the Fastest Growing Automotive Material Today

But, that’s not all. Drive Aluminum outlines 6 reasons to explain why aluminum is one of the fastest growing automotive materials today:

• Safety – No aluminum-bodied vehicle crash tested by federal regulators earned less than a 5-star safety rating.
• Durability – The Humvee and other U.S. military vehicles for combat are made with aluminum.
• Sustainability – When compared to other competing materials, aluminum contributes the smallest carbon footprint.
• Efficiency – Aluminum can offer the strength of steel in targeted applications at less weight, making it the more efficient option.
• Performance – Accelerate faster with shorter distances needed to break when you drive with aluminum.
• High Value – By reducing a vehicle’s overall weight, aluminum stands out as a cost-effective material.

Individually, any one of these key benefits would make a great case for material use in autos. Taken altogether, they present a 3-pronged explanation for why aluminum has become today’s fastest growing automotive material—it’s great for consumers, valuable to automakers, and also satisfies federal regulations in an age of heightened sustainability concerns.

Key Benefits of Automotive Aluminum

Let’s dive into each of those benefits a little deeper.

Safety

When purchasing a vehicle, safety is no doubt a top priority. Annual motor vehicle fatalities in the U.S. hover around 35,000, amounting to over 3.5 million since the late 19^th century. In response, the National Highway Traffic Safety Administration (NHTSA) has improved upon and tightened safety guidelines, and fatalities are on the decline. We can’t attribute the decline in fatalities to aluminum alone, but having a consistently high crash test rating is encouraging. It builds confidence and saves lives.

Durability

In the event 5-star crash test ratings are not enough to prove the durability of the material, learning that aluminum has become a gold standard for military and defense vehicles might sooth any safety concerns. It’s good to know that the car you drive is armor-tough. For example, many of the 5xxx series aluminum grades make their way into both consumer and military vehicles.

Sustainability

Not unlike safety concerns, sustainability is important to consumers, automakers, and regulators alike. Understandably so, as having a smaller carbon footprint affects everyone. While producing primary aluminum can require a significant amount of energy, aluminum is a recyclable material. Nearly 75% of all of the aluminum ever produced is still in use today.

Efficiency

It’s sustainable beyond that. Because aluminum has an excellent strength-to-weight ratio it is a light material that maintains quality strength. For automakers, this translates to less material needed for equal efficiency measures.

Performance

When performance standards can be met with aluminum, the resulting vehicle is lighter. A lighter vehicle means less work on the engine, and less fuel required.

Value

This creates a high-value sweet spot, which greenlights aluminum as a preferred material.

Why Automotive Aluminum Over Automotive Steel?

Since carmakers strive to produce lighter, safer, more fuel-efficient vehicles, technology improvements have advanced the performance benefits of aluminum in cars while proving better suited in certain cases to meet new challenges than steel. While dual-phase sheet steels and other AHSS steels specifically engineered for automotive light-weighting exist and continue to be developed, aluminum offers an immediate solution with maximum weight reduction.

Aluminum has the incredible ability to be alloyed with elements ranging from copper to magnesium to silicon, and each of these particular alloy compositions highlight various performance qualities of aluminum itself. For example, the 5xxx series aluminum grades mentioned above are magnesium-based grades. Magnesium produces a harder and stronger aluminum that demonstrates excellent impact resistance.

While steel is an incredibly tough material, it’s also heavy. It can also endure the impact necessary for vehicles, but it has a high-cost in terms of added weight to the vehicle. The weight of steel—assuming it is not high strength or ultra-high strength steel specifically designed with better strength-to-weight ratios—puts strain on the engine and leads to lower fuel economy and higher emissions. These are all poor outcomes for stakeholders.

Since the auto industry must meet new performance requirements to meet federal and consumer demand, automotive aluminum stands out as a popular and practical choice.

Rise in Demand for Electric Cars

Electric vehicles are made differently than internal combustion powered vehicles. Lithium batteries are heavy, and high range is difficult to achieve. Things like whether the air conditioning or heat is being used will impact how many miles are possible to achieve with an electric vehicle battery before charge is required.

Something is required to offset the weight of batteries, and the variables associated with consumer use. Aluminum is a pragmatic solution. It extends range and offsets battery weight and costs by being a light material. In addition to the increased applicability of aluminum sheet, electrification also increases demand for aluminum extrusions.

6xxx series aluminum, which is magnesium and silicon based, offers the highest quality extrusion capabilities that electrification requires. For automakers extrudability signifies easy workability for custom parts, which distinguish the look and feel of cars that is central to vehicle branding and competitor differentiation. It also helps when the same auto manufacturer can use, say 6016 aluminum sheet for both a compact economy car and a pickup truck or SUV. High-pressure aluminum diecast parts are also common for things like battery housings, motor housings and body structural components.

Most Common Aluminum Grades

• 1100 – this grade is commercially pure aluminum. It is the softest and most ductile aluminum grade available. Heat insulators are a common application for this grade.
• 3003, 3004, 3105 – these manganese-based non-heat treatable alloys offer moderate strength and have great formability, workability, and drawing capabilities, as well as excellent corrosion resistance. You’ll see these three grades in non-structural auto body components, bracketry, & HVAC components, such as radiators, trans coolers, and other temperature management components.
• 5052, 5454, 5754, 5182, 5083, 5251, 5005 — these alloys offer high strength excellent formability, weldability, and corrosion resistance making these 5xxx series aluminum grades some of the most functional and serviceable grades available. Their applications are numerous, from fuel tanks and suspension to auto body paneling. This series is widely used in BIW structural applications.
• 6082, 6181 — lightweight, durable, and showcasing the best extrudability capabilities.
• 6016, 6014, 6022 — these are the lower copper variant sheet alloys used primarily in applications where formability and hemming performance are needed over yield strength in body panel applications. These 6xxx series grades have outstanding surface quality for auto body coverings in doors, trucks, roofs, and fenders, combined with high strength and corrosion resistance.
• 6005, 6111, 6451 — these are higher copper sheet variants used when post-aging strength is the most desired property in body panel applications.
• 7003, 7046, 7075 — these grades showcase very high strength, but low elongation which limits cold sheet forming applications. However, with elevated temperature forming of 7075 for example, complex geometry can be obtained and is used for structural applications for crash performance, like impact beams, A/B pilars, roof headers and bumper reinforcements.

Each of these common aluminum grades have been purposed in automotive aluminum to meet the unique needs of the auto industry. Through sheer versatility and high-value aluminum continues to satisfy consumers, manufacturers and regulators.