When it comes to fuel economy, weight is the enemy: A heavier vehicle requires more fuel. Naturally, more manufacturers are turning to lighter-weight aluminum for parts and panels.
“The first aluminum parts were radiators, when aluminum displaced copper and brass,” says Doug Richman, of the Aluminum Association’s Aluminum Transportation Group, and vice-president of engineering and technology for California’s Kaiser Aluminum.
“Then it was castings, such as engines, transmissions and master cylinders. The next frontier will be high-volume applications of body structure, closure panels, engine cradles and instrument panel support beams.”
Automakers have traditionally been slow to adopt extensive use of aluminum for several reasons, the primary one being cost.
“They do have some cost premiums,” Richman says. “It’s not huge, but the value of weight reduction was driven by the economic value in fuel savings. As the cost of fuel goes up, the value to the customer of a lighter vehicle goes up, and so the more expensive technology becomes practical.”
Challenges also included aluminum’s unique properties, which meant that carmakers had to learn new ways to stamp parts, and then fasten and weld them. Even handling techniques have to be modified, since aluminum scratches and dents more easily than steel, and it can’t be picked up with a magnet. The cars must also be crash-tested, but Richman says that cars with a high percentage of aluminum can be safer than the steel-bodied cars they’re replacing.
“What we’re seeing is aluminum engineering design as a safer alternative.”