24 Jan 2022
Dynamic beam laser with a galvo scanner offers new capabilities for welding and laser powder bed fusion.
The two partners say that the combination of Civan’s dynamic beam laser (DBL) with Smart Move’s state-of-the-art laser scan head means that customers are now able to change beam-shape orientation on the fly - meaning that more complex geometries can be formed.
That is thanks to Civan’s patented coherent beam combination, which is able to modulate beam shape at speeds of up to hundreds of megahertz without any moving parts.
“This entirely new category of lasers uses optical phased array coherent beam combining to merge many single-mode laser beams into a larger beam,” explains Civan.
“Each laser’s light overlaps with other beams in the far field, creating a diffraction pattern that makes it possible to manipulate the beam shape in real time.”
Phase modulators are used to control the individual beams, and the resulting interference pattern can be adjusted to maximize the beam spot position and produce a variety of shape patterns inscribed by the beam's motion.
Faster speeds; no spatter
The DBL approach can also control shape frequency, shape sequence, and depth of focus, Civan says, adding that control of those parameters offers a powerful way to optimize evaporation in the capillary, the flow in the molten pool, and the solidification of the melt for any laser materials processing application.
“Such control does away with pore, spatter, and crack formation - while increasing feed rates and speeds in welding and additive manufacturing applications,” claims the firm.
Civan CEO Eyal Shekel said: “Smart Move makes the fastest and most accurate scanning solutions available. The integration of our dynamic beam laser with state-of-the-art scanner technology allows welding and laser powder bed fusion customers to not only improve welding feed rates and additive manufacturing speeds, but also make previously impossible applications possible.”
The two firms have now completed development of a scanner for laser powder bed fusion, which has been delivered to a major systems manufacturer.
Civan says that another scanner has been produced for laser machining specialist BBW Lasertechnik, and will be integrated in one of its welding systems.
Smart Move and Civan are also now collaborating with the Fraunhofer Institute for Laser Technology (ILT) to develop a process for welding bipolar plates used in fuel cells.
Each fuel cell is said to need 300-400 bipolar plates, each with a thickness of hundreds of microns, and with a weld seam of 3-6 meters.
“The demand for bipolar plates is high, but previous efforts by other companies to increase bipolar plate welding speed to more than 0.5 m/sec have resulted in welding defects,” say the two firms.
Under what is called the “Eureka” project, the two firms and Fraunhofer ILT are now working to incorporate a galvo scanner and advanced real-time process monitoring to control “beam wobble” at megahertz frequencies, something that should increase welding speed and accuracy, without introducing defects.