Laser processing head for direction-independent buildup welding

A welding head for laser-assisted or laser-based buildup welding with a coaxial arrangement of the weld deposit feed is presented. Several individual beams are bundled in a focal point below the welding material supply. In general, all meltable materials (e.g. metals, glass or polymers) can be processed with this system.


In current arrangements for laser welding, it is often necessary to use a lateral arrangement of laser and torch or laser and wire. Hence, the buildup welding process is direction-dependent. Furthermore, additional axes are necessary to create complex components. The complex process is therefore usually associated with complex programming.

Our solution

In the laser-assisted coaxial gas metal cladding method presented here, the torch of the welding source is arranged vertically. The laser beams are arranged coaxially around the torch and focused below it. Both, the arrangement and the number of individual beams can be varied. The coaxial arrangement means that process control is independent of direction. Furthermore, it is possible to control the power of the individual beams depending on the welding situation by using the direct diode principle with six installation positions. If one beam source is omitted, it is possible to install measuring equipment in the free installation position (pyrometers, cameras). It is also possible to use the process without an arc or with a powder stream nozzle. Another advantage of the direct diode principle is the possibility of using laser diodes with different wavelengths. Furthermore, the system is designed to be flexible in terms of the choice of optical components (focusing lenses or optical fibers), so that quick changeovers can take place. Changing protective glasses, which protect the optical components from emissions, such as welding fumes and spatter, is just as easy thanks to the modular design of the process head. Furthermore, the process head can be equipped with a tungsten inert gas welding torch, which further increases the range of applications. A beam splitter in the form of a reflectively coated pyramid is used for beam guidance. It splits the beam, guides it around the wire guide and brings it together below in a focal point.

CPA-2221-LZH-imagePrinciple of coaxial laser wire buildup welding with pyramidal beam splitter according to the invention. (source: Laser Zentrum Hannover e.V.)


  • Highly flexible use due to possible adaptations
  • Wavelength adjustable, optics interchangeable for each beam path
  • Coaxial beam guidance
  • Power of the beam paths separately adjustable
  • Installation of additional measurement technology possible


  • Metal inert gas (MIG) buildup welding
  • Laser wire buildup welding
  • Laser powder buildup welding
  • Laser soldering (trifocal)
  • Buildup welding of generative structures and coatings
  • Joint welding

Development Status

Process successfully tested on different surfaces (glass, glass-ceramic and plastics). Further development towards industrial applications in progress.

Patent Status

European patent application filed: EP21178803.9
Patent applicant: Laser Zentrum Hannover e.V.


Dr. Mirza Mackovic
Patent Manager Technology
E-Mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Phone: +49 (0) 551 30724 153
Reference: CPA-2221-LZH

Tags: Laser physics and optics, Physics and Technology & Software


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