Modern fiber laser with tunable beam shape provides new application areas and integration into individual production processes

Versatile and fast welding

News – Fraunhofer IWS Dresden / October 14, 2020

A novel multimode fiber laser allows individual modifications of the laser beam shape within a few milliseconds – without using external optical elements. Researchers at the Fraunhofer Institute for Material and Beam Technology IWS can now realize various applications from heat conduction welding to deep penetration welding with only one laser system. Following intensive tests of the high-power fiber laser in Dresden's laboratories, industrial customers are invited to cooperate with Fraunhofer IWS experts to discover the laser’s advantages for their specific applications.

New fiber laser with tunable beam characteristics facilitates laser beam welding of thick and thin wall thicknesses without changing the welding optics.
© Fraunhofer IWS Dresden
New fiber laser with tunable beam characteristics facilitates laser beam welding of thick and thin wall thicknesses without changing the welding optics.
Flexibly adjustable beam modes: small beam diameter with high intensity, e.g. for deep penetration welding (l.), and large annular laser beam, e.g. for heat conduction welding (r.).
© Fraunhofer IWS Dresden
Flexibly adjustable beam modes: small beam diameter with high intensity, e.g. for deep penetration welding (l.), and large annular laser beam, e.g. for heat conduction welding (r.).

The Fraunhofer IWS technology field "Joining" offers innovative laser beam welding processes and technologies. They are applied to generate crack-free welded joints of hardenable and high-strength steels, cast iron as well as aluminum and special alloys. Our comprehensive know-how in materials science, even interdisciplinary, and our modern laser system technology enable our joining experts to react quickly and flexibly to specific customer requirements. A modern multimode fiber laser, which can be programmed according to customer requirements, is now included in our portfolio.


Flexible beam mode modification for high-power fiber lasers

The Fraunhofer IWS has recently started using a four-kilowatt multimode fiber laser with programmable beam quality for process development. In contrast to existing solutions, it allows a fast, adjustment of laser beam shape without using external optics in within less than 30 milliseconds – even during the welding process and at full power. A majority of fiber laser systems on the market have fixed beam properties and are designed for a limited range of metals and component thicknesses due to their specified welding beam diameter. After an intensive testing period of the new fiber laser at Fraunhofer IWS, customers can use the flexibly adjustable laser output to choose a small beam diameter with high intensity, a large circular beam, and many shapes in between. "The new fiber laser offers our industrial customers the possibility to perform various applications from heat conduction welding to deep penetration welding with only one laser system. The use of universal optics provides the significant advantage of joining both thick and thin metals quickly and with the highest weld seam quality. The costs, complexities and set-up times associated with the use of external optics, all of which particularly relevant to medium-sized companies, are eliminated by the new laser source," explains Dr. Dirk Dittrich, group manager "Laser Beam Welding". We are pleased to provide advice on how to integrate the laser and our joining know-how into new or existing processes 

Example of a tuned beam shape of the new fiber laser.
© Fraunhofer IWS Dresden
Example of a tuned beam shape of the new fiber laser.
Multimode fiber laser welding process. The laser beam shape and geometry can be changed/adjusted/modified in less than 30 milliseconds - even during the welding process – without external optics.
© Fraunhofer IWS Dresden
Multimode fiber laser welding process. The laser beam shape and geometry can be changed/adjusted/modified in less than 30 milliseconds - even during the welding process – without external optics.

IWS researchers provide support/at hand for practical tests and industrial projects

The group "Laser beam welding“ offers a wide range of services to partners. These include customer-specific process development and consulting as well as system optimization and the implementation and monitoring of procedures. Dittrich's "Laser Beam Welding" team maintains a long-standing cooperation with the US company nLIGHT, manufacturer of the tunable beam shape fiber laser, a partnership built significantly on the exchange of scientific results. The IWS experts analyze the lasers developed by nLIGHT, research suitable applications and integrate/implement them into individual production processes at various industrial customers. Dittrich emphasizes: „The IWS' cooperation with different laser manufacturers offers benefits to customers in the automotive industry, aerospace, mechanical and tool engineering as well as in energy and environmental technology. We develop customized system solutions aiming at more efficient and sustainable production. The cooperation with the IWS does not stop with the laser's implementation into serial production. Digital IWS technologies, e.g. sensor systems and artificial intelligence, continue to support our customers in order to achieve the best possible welding results at all times."