How Aluminum Is Shaping Up for Motown
Switching from steel to aluminum for car bodies would slash the weight of Detroit's buggies by more than a third, which would boost mileage and reduce air pollution. Except for trunk lids and some hoods, however, aluminum remains a stranger to body-panel factories. That's because it's tough to stamp into stylish shapes. Now researchers at Ohio State University are developing a kinder, gentler technique.
Car-body panels would still be produced in big stamping presses, but the final touches would be hammered out by electromagnetic pulses. This hybrid approach compensates for aluminum's poor "plasticity"--it will stretch only about 30% before it thins out and then ruptures, vs. 100% for steel. So materials scientist Glenn S. Daehn dreamed up a better idea: stamp out a rough shape, then use energy pulses from electromagnetic coils in the top half of the die to progressively push the aluminum into the detailed crevices.
After spending a decade and more than $1 million on the concept, Daehn's team recently produced aluminum door panels that are almost identical to the steel parts now being used. Currently, he's working with Pacific Northwest National Laboratory to develop the computer models and software tools that Detroit will need when auto engineers finally give aluminum a thumbs-up.By Otis Port