Aluminum is important to our way of life. Its resistance to corrosion, light weight, high strength, and recyclability make it an essential and often preferred material. Now these properties are making aluminum a material of interest in the automotive industry as well, possibly giving even advanced high-strength steels (AHSS) a run for their money.
Aluminum is more expensive than steel, and doesn’t weld as easily. So why is this metal getting so much attention in the car industry? It all has to do with new fuel emissions regulations.
The National Program for greenhouse gas emissions (GHG) and fuel economy standards was developed jointly by the Environmental Protection Agency (EPA) and the National Highway Traffic Safety Administration (NHTSA) with the goal of halving the amount of carbon emitted by light duty cars and trucks by 2025.
According to the U.S. EPA, the program will save consumers an estimated $1.7 trillion at the pump, reduce carbon pollution by 6 billion metric tons over the lifetimes of new vehicles sold in model years 2012-2025, and reduce America’s dependence on oil by more than 2 million barrels per day by 2025. The standards apply to light duty cars and trucks in model years 2012-2016 in the first phase and 2017-2025 in the second phase.
In February of this year, President Obama directed the EPA and the NHTSA to issue similar standards for medium- and heavy-duty vehicles by March 2016. According to a fact sheet provided by the White House, this second round of fuel efficiency standards for medium- and heavy-duty vehicles builds on the first round covering model years 2014 through 2018, which is projected to save vehicle owners and operators an estimated $50 billion in fuel costs and save a projected 530 million barrels of oil. Medium- and heavy-duty vehicles are currently the second-largest source of greenhouse gas emissions within the transportation sector (passenger cars and light trucks are the largest source).
To comply with these new standards, car manufacturers must achieve an average MPG of 54.5 miles across their fleets by 2025, thus the interest in replacing steel with lighter weight aluminum.
While automotive components such as engine blocks and wheels have long been made from aluminum, constructing the car body from aluminum is a relatively new idea. According to The Aluminum Association, here are some reasons why aluminum’s time has come:
- Aluminum is lighter than steel, so aluminum vehicles can go farther on less gas, accelerate faster, brake and handle better, and haul and tow more.
- Aluminum offers improved safety, strength, and durability compared to steel. Its lighter weight provides more dent resistance because body panels can be made thicker, and its strength makes it more able to withstand a crash impact.
- Aluminum is 100% recyclable and nearly 90% of automotive aluminum scrap—more than a half-million tons a year—is recovered and recycled.
- Aluminum has a small carbon footprint. A fleet of aluminum vehicles saves the equivalent of 44 million tons of CO2 emissions.
Making entire cars out of aluminum will require major investments in new machines that stamp car parts. Aluminum cars would be put together differently, requiring changes in assembly lines. Most importantly, aluminum manufacturing industry itself must be ready to take on the demand.
Primary aluminum production is a complex process, dependent on a consistent supply of raw materials and huge amounts of energy. Production methods have improved signiﬁcantly over the past decade, and recycled materials are accounting for a larger portion of the total aluminum supply. These shifts in production require producers to be aware of, and willing to adopt, the latest technologies to ensure the finished material meets precise automotive manufacturing specifications.
Among these technologies are elemental analysis instruments to ensure the correct alloys are combined in the right percentages, as well as aluminum gauges that provide noncontact thickness measurement in the high-speed production environment of aluminum cold strip mills. Such tools are the key to efficient, cost effective aluminum manufacturing and will play a significant role in the future automotive industry.
Given the infrastructures changes that would be required by a switch to aluminum as the primary automotive metal, many car manufacturers are pursuing the AHSS to meet new fuel emissions requirements. These lighter-weight, higher-strength steel components also provide improved fuel economy by making car body structures stronger but lighter in weight.
According to the American Iron and Steel Institute, AHSS not only increase safety and fuel economy, but compared to other materials, they help reduce CO2 emissions over the life cycle of the vehicle. To learn more about AHSS, see our blog, “New Steel Grades Drive PMI Programs in Automotive Manufacturing.”