Dana Ready to Begin Spark-Free Welding

Dana Corp. has been talking about magnetic pulse welding for years as a technology that will make for easier assembly of truck frames and reduce weight significantly by allowing steel to be joined with dissimilar lightweight materials, such as aluminum, magnesium or titanium.

Next year, Dana will use magnetic pulse welding for the first time to produce a driveshaft that is mostly aluminum. The ends will be made of steel, where the torque demands are the most severe. Magnetic pulse welding allows aluminum and steel components to be joined in a super-tight molecular bond. The process requires no heat or welding wire and minimizes scrap.

Bruce Butcher, vice president-structural solutions group, says at last month's automotive Management Briefing Seminars in Traverse City, MI, that the company will use magnetic pulse welding to commercially produce a driveshaft next year. But the company will not identify the plant where the process will be applied or the vehicle to receive the driveshaft.

Butcher tells Ward's he hopes the process will be production-ready for frames, engine cradles and other structural components by the end of this year. In the meantime, extensive testing is under way.

“It's a simpler process for driveshafts than it is for structures because of the shape,” Butcher says. “We're very confident that we have a good process for driveshafts. Now we're making sure it's a good process on structures.”

Dana has used magnetic pulse welding to build prototypes that have been through corrosion and durability testing by the supplier and its customers. “Does it meet the long-life corrosion tests; does it still hold up? The answer is yes,” Butcher says.

Ultimately, Butcher hopes Dana can use magnetic pulse welding to produce an entire spaceframe, perhaps made of steel, aluminum and magnesium. Steel would be necessary only for the highest-stress portions of the frame - the center side rails. No word yet as to the potential weight savings. In a truck frame application, Dana determined that three aluminum cross members could be substituted for steel and save 19 lbs. (4 kg) per frame.

The auto industry can benefit from magnetic pulse welding because it is cleaner, safer and simpler and ensures more consistent joints than arc welding. It's also distortion-free, another advantage over traditional welding.

Butcher's goal is to make the process “cost neutral” when compared to traditional welding. But there is potential for significant savings by eliminating smoke collectors and welding wire.

Meanwhile, Butcher has good news about Dana's plant in Campo Largo in southern Brazil. The plant produced the heralded “rolling chassis” for the Dodge Dakota pickup, but DaimlerChrysler AG stopped producing the truck in Brazil two years ago.

Dana had to pull the plug on the rolling chassis and its brand new plant, which was held up as a shining example of supplier capability. Dana assembled frames and installed axles, wheels, brakes, springs and fuel tanks before completed chassis were shipped to DC in Curitiba for final assembly.

After nearly two years of sitting idle, the facility is producing heavy truck chassis for AB Volvo, which assembles trucks nearby in Curitiba.

Dana produces side rails at its plant in Sao Paolo and ships them to the Campo Largo plant for frame assembly. The supplier then delivers the frames to Volvo on a just-in-time basis.