The use of aluminum in automotive applications has been climbing steadily for the past 30 years, according to a study by Ducker Worldwide LLC, Troy, Mich., commissioned by the Aluminum Association's Auto and Light Truck Group (ALTG).
The average aluminum content in North American light vehicles was 319 pounds in 2006, up 3.9 percent from 307 pounds in 2005 and nearly four times the 81-pound average in 1973. Aluminum last year surpassed iron as the second most commonly used material in autos, trailing only steel, ALTG said.
"Aluminum has done a great job of penetrating the auto industry over the last 30 years," said Subodh K. Das, director of the Center for Aluminum Technology at the University of Kentucky and president and chief executive officer of Secat Inc., Lexington, Ky., the organization that commercializes the center's research.
Aluminum's use in autos is expected to continue on a growth trend, Mike Bull, head of ALTG's technical committee, said. "Certainly, the trend is heading in that direction. We see steady and improved growth for aluminum in the automotive sector."
Recent projections suggest that global auto production will soon reach 100 million units annually, Das said. Even with a conservative average of 300 pounds of aluminum per vehicle, that equals about 15 million tonnes of aluminum in automotive applications annually, representing nearly 40 percent of the world's current 38-million-tonne-a-year aluminum market.
Economic, environmental and consumer factors, such as the price of fuel, will continue to drive aluminum use in autos, Bull said. This will come in terms of both aluminum-intensive vehicles, defined as those with more than 500 pounds of aluminum content, and large-volume models that use less aluminum per vehicle but by virtue of their production run size will have a significant impact on aluminum consumption.
The growth in auto aluminum use will come on three major axis, Bull said. He pointed to aluminum's displacement of other metals in individual components, such as hoods, trunks and suspension components. "There is a growing level of comfort among original equipment manufacturers (OEMs) in choosing aluminum components like control arms," he said. "We see incremental continued adoption of suspension elements."
Growth also will come from the "high content" vehicles containing more than 500 pounds of aluminum. "There will always be some fairly aluminum-intensive vehicles in the market," Bull said. And growth will come from vehicles with full aluminum structures, such as the Jaguar XJ and the Audi A8.
There is also a move to use more aluminum in sport utility vehicles (SUVs), Bull said. Manufacturers are using aluminum in the roofs of SUVs to lower the center of gravity in the vehicle, as well as in the rear liftgate in an attempt to reduce the rear-axle mass load.
Another avenue for aluminum growth comes from secondary weight savings, he said. If an automaker can reduce the mass of a vehicle using aluminum, the manufacturer can then achieve a similar performance with a smaller engine because the engine will have less mass to move, and similar weight and cost savings also can be realized elsewhere in the drivetrain as overall vehicle weight is lowered. "Aluminum gets the weight spiral going down with secondary weight savings," Bull said.
One area where secondary weight savings could play an even greater role is in vehicles with alternative fuel and energy technology engines like hybrids and others. These engines are usually more expensive to manufacture, Bull said, and the cost grows in step with additional horsepower. Lightweighting such a vehicle with aluminum components reduces the need to add more power to achieve performance targets, leading to an equation in which it might be less costly to lightweight the vehicle than add power to the engine. "We're quite keen to see how this plays out," he added.
Although much of the growth in aluminum use in autos will come from body and structural applications, there is still room for growth in castings, such as engine blocks—an area targeted for expansion by Tenedora Nemak SA de CV, San Pedro Garza García, Mexico, a subsidiary of Mexican conglomerate Alfa SA de CV.
Nemak might even be a potential buyer of the automotive castings business of Alcoa Inc., Pittsburgh, one analyst said. The aluminum producer expects to sell the business by the end of this year. "There aren't a lot of large foundry companies any more, and Nemak is quite good at what they do," the analyst said. "They are a potential buyer of Alcoa's castings business. The potential for growth for aluminum is still high under the hood in castings and structurals, which are the types of things the Alcoa business makes. It would be a good opportunity for Nemak."