Pulse Welding Arrives

After years of engineering, testing and pitching its proprietary magnetic pulse welding manufacturing process for joining dissimilar metals, Dana Corp. appears to have a high-volume customer.

The Toledo-based supplier plans to use the innovative spark-free welding method to produce a driveshaft for a high-volume light truck produced in the U.S. by one of the “Big Six” auto makers in 2006 for an '07 model. Dana and the OEM customer are close to finalizing the purchase order.

Assuming that program launches successfully, Dana expects other auto makers will want the technology for their driveshaft programs as well.

“They'll see the advantage of the application, and of course other competitors will take their stab at the technology or some alternative to it,” says Mike Laisure, president of Dana's Automotive Systems Group, as the supplier dedicates a new technology center in Maumee, OH. “It won't just be a little pet project on the side.”

Driveshafts traditionally are arc-welded — a hot, messy and potentially dangerous process. The added weight from the welds at each end of the shaft can cause “distortion.” To prevent noise and vibration problems when the driveshaft spins, manufacturers such as Dana have to weld on counterweights for balance.

Magnetic pulse welding minimizes the need for counterweights because it ensures much more consistent joints through a super-tight molecular bond. The process requires no heat or welding wire, it minimizes scrap and it's clean and distortion-free.

“We could get to the point where the driveshaft is balanced in the manufacturing process, and we don't even need the extra equipment to spin them and balance them,” Laisure says.

The technology's most significant attribute, however, is that it allows different metals to be joined — a feat not possible with arc welding. As a result, most driveshafts are made of welded steel components, even though steel is not necessary throughout the entire shaft.

Dana intends to build driveshafts by using magnetic pulse welding to join aluminum and steel components. The supplier estimates this first contract will result in weight savings of about 25% for the driveshaft.

Auto makers are eager to shave vehicle weight as they wrestle with federal fuel economy requirements, especially for bulky V-8-powered pickups and SUVs.

Although the 2006 launch represents the technology's high-volume light-vehicle debut, the supplier was close to using the technology for driveshafts in 2003 for low-volume commercial vehicles. But Dana sources say that contract fell through because the vehicle program was canceled.

Laisure says the technology is cost-competitive with conventional welding, and he expects magnetic pulse welding operations to be running in many of Dana's 13 driveshaft manufacturing and assembly plants in the U.S. by the end of the decade.

“I think once the market has a feel for the technology and sees the product and the performance, we will see an expansion,” Laisure says. “We will see some of the current technology we have being replaced by magnetic pulse welding.”

At the Society of Automotive Engineers World Congress, Dana showed an integrated independent rear suspension for fullsize trucks, and the supplier used magnetic pulse welding to join the module's aluminum structural cross members to the steel rails.

Meanwhile, Dana's new Automotive Systems Technology Center in Maumee, southwest of Toledo, will serve as the global engineering center for driveshafts and axles as part of the supplier's Torque & Traction Div., which accounts for $3.2 billion of Dana's $8 billion in annual sales.

The $45 million technology center has dynamometers for testing axles and driveshafts, and its “paperless” design capability springs from 3-dimensional computer modeling and advanced computer simulation. Testing and analysis capabilities include a full metallurgical lab with X-ray diffraction and scanning electron microscope.

The Maumee Technology Center employs 500 people and consolidates operations from seven other Dana facilities. Of the 500, 150 relocated from Dana's former engineering facility in Fort Wayne, IN, and 160 relocated from nearby Holland, OH.