ALUMINUM HOLDS GREAT ALLURE FOR AUTO COMPANIES that want to boost fuel efficiency by reducing the weight of the car. But unlike steel, the lighter metal tends to tear during molding. To make it more elastic, researchers at Ohio State University are resurrecting a technology from the 1950s, which literally explodes thick sheets of aluminum into forms.
Researchers trigger the explosion either under water or in the presence of a magnetic field. It generates shock waves that fling the metal into the mold at speeds as high as 220 meters per second, according to Glenn S. Daehn, a professor at OSU's Materials Science & Engineering Dept. Another advantage: Instead of the typical two-sided dye-casts, with their male and female parts, this process requires just a single, one-sided dye.
Daehn says that Maxwell Technologies and other companies developed this approach, called electrohydraulic forming, 40 years ago. Then they put it aside while they pursued more lucrative defense contracts. Now, OSU is re-evaluating it with General Motors Corp. and Rockwell International Corp. Daehn is also talking with Aluminum Co. of America, which has developed an all-aluminum car with Audi of Germany. Alcoa is investing in a new auto parts plant in Ohio and will consider using electro-hydraulic forming as part of the production process.