Conventional gas metal-arc welding is inexpensive, but difficult to control. Since the arc naturally follows the path of least resistance between the electrode and the weld metal, the position of the weld cannot be exactly determined, which can have a negative effect on the welding results. If a low power laser beam precedes the arc, the arc follows it and is stabilized. Thus, not only the welding seam quality is improved, but the welding speed can also be significantly increased.
This new process has already been subject to tests for conventional, high-strength, and higher-strength steels as well as for aluminium materials. At the same welding depth, the welding speed could be increased by up to 100 percent. Also, oscillating and contoured welding seams and complicated welding shapes can profit from this new process.
This process principle is also being tested for deposition welding. By using the so-called "laser-guided gas metal-arc deposition welding", the efforts and costs for the repair and wear protection of large-sized tools can be significantly reduced. This is especially interesting for molding tools or injection molding tools or for large tools used in mining or tunnel building.
"We've already reached a 100 percent increase in speed for metal active gas welding (MAG)," says Jörg Hermsdorf, engineer at LZH. "We hope to achieve similar results for deposition welding. A mobile system for deposition welding could be especially interesting since repairs could then be done on site. This would eliminate the tools having to be removed or transported, which in turn leads to long down times."
The "FÜLAS" project (welding) is supported by the German Federal Ministry of Education and Research and the Project Management Agency Karlsruhe. The project "PROGENIAL" (deposition welding) is supported by the BMBF under project management of the Association of German Engineers.
For more information, contact Michael Botts at [email protected]