The opportunities for aluminum applications are great. That was true five years ago. It will probably be true five years hence. For some reason (probably cost), the proliferation of aluminum has been rather limited. In fact, an argument could be made that the proliferation, with the exception of comparatively and actually exotic vehicles—like the Lotus Elise and the Ferrari Modena 360—, has been limited to one brand: Audi. There are, for example, the A8 and the A2 (the last named is not available in the U.S.). With these two vehicles, Audi is showing that aluminum-intensive vehicles can be produced. The German company is making use of such things as hydroforming, laser welding, and self-piercing riveting to assemble these vehicles, processes that are not particularly common in North American operations. To be sure, there are examples of all of these in North America, some of which are rather impressive. For example, hydroforming of truck frame rails (which include some laser processing, albeit, generally, cutting, not welding). But these rails are made of steel. Still, to be fair, it is estimated by American Metal Market that in 2002 there will be an increase in the amount of aluminum used in the average North American vehicle from 255 lb. to 268 lb.
Anyway. . .
At The Aluminum Association’s 22nd Annual Automotive Aluminum Design and Fabrication Seminar in Livonia, Michigan, this past October, there were A2s in the parking lot. The license plates on these vehicles indicated that the cars are in the fleets of vehicle manufacturers. Obviously, they are of interest to domestic manufacturers in more than a cursory manner. (And what better to drive to an aluminum conference?) There was a military Hummer out front: an aluminum-intensive vehicle that is, itself, intensive. Speaking of the military, Paul Skalny, associate director of the National Automotive Center, which is the U.S. Army’s official link to industry and academia and is working to develop dual-use technologies for defense and commercial applications, noted that the Army wants to get better miles per gallon for some of its vehicles—like lightening tanks so that they can get 27 mpg rather than 9 mpg. “Our goal,” he said, “is to transform the U.S. Army to a lighter, more mobile, more fuel-efficient force by 2012, and we will only get there with active participation from the aluminum industry.” And when the U.S. Mail was delivered to that venue, there is a good chance that it was transported in one of the more than 140,000 aluminum-intensive postal delivery vehicles that Grumman Olson has built for the U.S.P.S. since 1987, of which, according to Tom Dolan, Grumman Olson’s engineering manager, only about 200 have been retired.
Dr. Andrew M. Sherman, senior staff technical specialist, Manufacturing Systems Dept., Research Laboratory, Ford Motor Co., is a strong proponent of aluminum. He noted at the seminar, “A good fraction of our cars should be in aluminum.” Yet they aren’t. And he pointed out that the if you take out castings—applications like engine blocks, for example—and look at where aluminum is being most widely used in vehicles today, it is in the heat exchanger, or radiator. He admitted that in the body-in-white “an insignificant fraction” of vehicles are using aluminum extensively.
While he is a proponent, Sherman is not naïve. He understands that there must be some serious work done in order to make aluminum a more attractive material for automakers to use, especially given that the material cost and the manufacturing cost are higher than they are for steel. Among Sherman’s recommendations for making aluminum a more favorable material:
- Design. Optimize the design so that less material is used; increase material strength so that there is no compromise in vehicle build.
- Scrap. Take a careful look at scrap generated in stamping. Develop efficient part layouts to minimize it. Sorting technology and plant practices in handling scrap need to be assessed.
- Material development. More efficient smelting and sheet production methods need to be developed. Sherman suggested that continuous casting is the way of the future for aluminum alloys.
Sherman also discussed the need for a better business case to be made for aluminum use. He noted that there is the possibility that the higher material cost could be offset through an examination of overall cost reduction. That is, if the vehicle body weight is reduced, there can be secondary weight savings realized by the downsizing of other vehicle components, including a smaller powertrain. That may make aluminum more attractive.
Ford, of course, is using aluminum for vehicles. Among those he cited are the Th!nk Neighbor (extruded aluminum space frame), the Aston-Martin Vanquish (which combines aluminum and composites), and the forthcoming Jaguar XJ. Come to think of it, all these are niche vehicles...
The Aston-Martin Vanquish: Aluminum shines here. But it is one of many limited-production cars that extensively utilize the material. Cost considerations continue to hold up more common use.