Faster welds, straighter parts and lighter vehicles are some of the benefits Dana Corp. says its new magnetic-pulse welding process will give automakers.
Magnetic-pulse welding, which Dana has been researching for almost a decade, uses magnetic fields and as much as 4,000 volts of energy to create a metallurgic bond between two similar or dissimilar metals in microseconds. Although used in nuclear reactor applications since the 1960s, the technology is new to the auto industry.
Dana initially is positioning magnetic-pulse welding to automakers as a way to produce driveshafts made of steel and aluminum. The ability to use more aluminum is timely for automakers who are looking for ways to take weight out of vehicles but want to use steel for some parts.
Most of the driveshafts the Toledo, Ohio, supplier produces are made entirely of steel. Although processes such as friction welding and metal inert gas welding also can be used to join dissimilar metals, Dana has concluded they are not suited for automotive applications.
Since Dana's driveshafts now are made of one type of metal, either steel or aluminum, the supplier uses metal inert gas welding. Each driveshaft typically requires two such welds.
Metal inert gas welding cannot be used to weld dissimilar metals, however. In addition, Dana says magnetic-pulse welding's other advantages over metal inert gas welding include:
It requires no gas, unlike metal inert gas welding.
It requires no filler metal, which is needed in metal inert gas welding.
It makes it easier to produce a straight tube. Metal inert gas welding, which pushes parts together and involves heat, can deform parts.
Unlike friction welding, magnetic-pulse welding does not require high temperatures. That means it can be used to weld dissimilar metals without destroying or modifying the characteristics of either metal.
Despite these advantages, Dana does not consider magnetic-pulse welding as a replacement for its other welding processes.
'We don't want to oversell magnetic-pulse welding,' said James Duggan, chief engineer of advanced design engineering for Dana's Spicer driveshaft division. 'It would be nice if we could use it on every vehicle, but I'm not so sure it makes sense on every vehicle.'
Applications such as passenger cars and light trucks, in which weight reduction is essential, will be Dana's initial target markets. Heavy-truck applications requiring diameters larger than 4 inches and heavy-walled sections have not been part of Dana's research. However, the supplier does plan to develop the process for its heavy-truck customers in the future.
A team of about 25 people is preparing magnetic-pulse welding for production, analyzing the components to be welded and developing the equipment.
Dana is putting the finishing touches on its 4-foot-by-8-foot prototype magnetic-pulse welding machine. The production machine, which will be much larger since it will include automation that is not part of the welding process, is scheduled to be installed at the supplier's plant in Bristol, Va., in the third quarter of this year.
'Our goal is to be able to support a 200,000-vehicle production level,' Duggan said.
Started in 1992
Dana would not disclose its investment in the machine or the technology. However, its work on the project can be traced back to 1992, when the company learned about magnetic-pulse welding from Russian scientist Boris Yablochnikov. Yablochnikov, now a Dana employee, currently heads the supplier's research on the process.
In its design of the production machine, Dana has made prototype driveshafts to be used in several platforms for automakers, including Ford Motor Co. and General Motors.
'We've had numerous phone calls from every other OE regarding this process,' Duggan said.
Despite not having a publicly acknowledged production contract, Dana is moving ahead with the goal of launching its production machine so it is ready for use in a 2002-model vehicle, probably a sport-utility, said Jerry Myers, Spicer driveshaft's senior design engineer in the advanced design group in Holland, Ohio.
Dana also is considering using magnetic-pulse welding in its space frame production. The supplier's research for this application is in the early stages.
Using the new welding process for space frames may be a couple of years away, said Bob Durand, director of advanced engineering and technology for Dana's Parish structures in Redding, Pa. A ladder frame is probably an easier product to make with this technology than a whole space frame, he added.
Myers realizes magnetic-pulse welding will not be an overnight success - especially since it initially may increase costs.
'I don't think we're really talking about converting the industry within five years,' Myers said. 'In general, it depends upon whether they (automakers) have a need, be it a CAFE, an NVH problem, some problem that causes them to want to change the driveline in a vehicle. ... As long as the old steel shaft is going to do the job, I don't see it as being changed to save a couple of pounds.'
Dana is not the only company trying to sell this technology in the auto industry. Pulsar Electro-magnetic Industrial Techno-logies of Israel, which has been producing magnetic-pulse welded parts for the appliance industry for about five years, also is working on test programs with automakers in the United States and in Europe.
Although Pulsar does not have any automotive customers, interest from automakers has increased in the last two years, said Serge Amar, Pulsar's vice president of business development.
Gail Kachadourian is a staff reporter at Automotive News