Strengthening the Bond: DaimlerChrysler Plant Adopts Argonne Weld Monitor

DaimlerChrysler's new state-of-the-art Indiana Transmission Plant (ITP) in Kokomo, Indiana, is abandoning its current laser weld monitoring systems in favor of a new technology pioneered by researchers at Argonne. The switch to the new technology, which has been further developed and commercialized by Spawr Industries, is expected to be completed by March 2000, according to company spokesman Jack Evanecky, area technical manager at ITP.

Throughout the automotive industry, laser welding has been rapidly overtaking traditional arc welding technology as the state of the art in recent years, but an easy-to-use, cost-effective means of detecting bad welds has been lacking. At ITP, welds were monitored by means of a cumbersome, expensive process that required immersing bulky parts in dunk tanks for testing via ultrasound.

The Argonne monitor detects heat from directly above laser welds as they are made ("real time" operation), so it doesn't add to cycle time. It provides feedback about the weld's surface, penetration depth, uniformity, the presence of impurities, spattering, etc. Spawr Industries (Lake Havasu City, Arizona) integrated the Argonne researchers' technology into a laser beam delivery system that permits better control of process variations.

DaimlerChrysler bought two of the Spawr IR weld monitors for its ITP plant earlier this year. Over the summer, Evanecky and Spawr's owners shared their ideas for improvements, "playing with the technology, exploring the limits and trying to get a handle on a good process window." At present, four of the new units are in operation on the plant floor, and seven more will be installed (and process windows established) soon, entirely replacing the more expensive conventional units. Cost savings, in equipment alone, are projected at well over a million dollars. In addition, by eliminating the need for destructive testing (once a routine operation) of welded components, the new technology is expected to cut scrap production by 10%.

Evanecky doesn't hesitate to predict that the applications will go well beyond their present efforts. "There's a whole lot of welding required in DaimlerChrysler's manufacturing operations," he says. "I really don't see any limit to the potential for using this technology."

Initial development of the IR laser weld monitoring technology at Argonne was supported through cooperative research and development agreements between DOE and Delphi Energy & Engine Systems and USCAR's Low Emissions Partnership (LEP), which consists of General Motors, Ford, and DaimlerChrysler).

Fall 1999