Laser scan head and beam shaper innovation boosts fuel cell production

16 Mar 2022

Partnership of Scanlab, Blackbird Robots, and Holo/Or developing significant laser 3D printing concepts.

Scanlab, a manufacturer of high-end scan heads, and sister companies Blackbird Robotersysteme and Holo/Or are developing new system concepts for industrial laser applications – such as laser welding of bipolar plates and additive manufacturing.

The novel scan setup – integrating tailored beam shapers – shows the potential to nearly double the productivity of welding bipolar plates for hydrogen fuel cells, for example, say the partners.

Fuel cell technology was considered a niche market for a long time. Due to the transition phase in energy generation and the search for alternative drives, the market demand might grow notably. For more efficient mass production, an increase of throughput in welding of metal bipolar plates, used to build the stacks in a fuel cell, is needed.

High welding speeds require fast scan systems and high power lasers, both available. However, it’s the welding process itself which determines the maximum reachable speed. Weld seam failures such as humping effects and undercut occur when a certain speed limit is exceeded.

Blackbird Robotersysteme set up a test rig integrating the 2D scan head intelliSCAN from Scanlab and Holo/OR’s latest development the Flexishaper, a full range adjustable beam shaper. The necessary beam shape was determined based on welding process simulations.

The layout of the utilized beam shaper is the result of a combined optical design, integrating both diffractive optical elements and scan system. The processing tests demonstrated to shift the speed limit of failure free welding speed from 45 m/min up to 70 m/min.

Adopting processing experience with DOEs

Thin sheet welding of bipolar plates has similar requirements to laser powder bed fusion processes. Both require scan field sizes up to 500 x 500 mm² with a typical processing speed around 1m/s and below. Also in metal 3D printing the processing speed is not limited by the speed of the scanner or the available laser power, but it is mostly the process itself which limits the throughput.

“Our joint company holding creates the trust that is necessary for such a close cooperation to explore innovative solutions. Only in a setup like this you can openly analyze the upcoming market requirements and transfer the outcome in an optical design,” said Georg Hofner, CEO of Scanlab.

“Our sister companies provide a construction kit for us, which we can translate into tangible benefits for our markets and customers based on our specific experience and application knowledge,” said Karl Christian Messer, CEO of Blackbird Robotersysteme.

“This is exactly the kind of cooperation that creates high value products by combining our unique beam shaping expertise with our sister companies market deep understanding,” said Israel Grossinger, owner and President of Holo/Or.

The next steps will be to test the laser welding concept in a larger scale setup and to pursue different applications in parallel. As the fiberSYS meets requirements of both LPBF and laser welding processes, the integration of DOEs into this scan system, particularly suited for multi head laser machines, was included in the development road map.