Product Code: ICAL07_309

High-Speed Laser Welding of Fuel Cell Metals
Authors:
Stanley Ream, EWI; Columbus OH USA
Presented at ICALEO 2007

As concerns about energy independence increase, government and industry are focusing more attention on improving energy utilization. Among the many opportunities for higher energy efficiency fuel cells have attracted considerable scientific, engineering, and popular attention. While most of the envisioned fuel cell devices and systems are still in the design stages, the potential manufacturers of these products are recognizing the need to develop manufacturing solutions to their unique fabrication challenges. Despite the tremendous diversity in fuel cell system designs one fabrication challenge appears frequently. Specifically, the need to weld thin (<0.5 mm), stamped sheets of stainless steels, for such devices as bi-polar plates, reformers, interconnects, and heat exchangers, has been identified as a common theme throughout the fuel cell development community. Recognizing this need, EWI has developed high speed fiber laser welding capability and related fixturing technology and has studied the welding performance of specific fuel cell related metals, including 304 stainless steel, Crofer-22, and Haynes 230 alloys. Each of these alloys has been successfully fixtured and welded at speeds up to 1 meter/second with excellent weld quality and gap tolerance. This paper will describe the system and fixturing methods used to perform this welding and the unique microstructures that result.