Product Code: PIC2008_705

Enhancement of Laser Welding Capabilities by Hybridization or Combination of Different Processes
Authors:
Dirk Petring, Fraunhofer ILT; Aachen Germany
Presented at PICALO 2008

The laser welding process is the most flexible fusion welding process industrially available. This is mainly due to the excellent variability of lasers spatial and temporal power distribution down to very small geometries and time scales. The result is high flexibility regarding e.g. weldable materials, achievable penetration depths and possible seam and joint configurations and thereby a big potential for application-specific process optimization. The degree of freedom for optimization is further enhanced and process limits are expanded, if hybridization or combination techniques are applied. This will be illustrated on the one hand by latest advancements in laser-MAG hybrid welding. Single-pass welding of high-strength steel plates with big gap tolerances, applicable e.g. in the yellow-goods industry, is investigated for thicknesses up to 30 mm. Substantial progress in hot crack prevention and fatigue resistance is achieved. On the other hand the manufacturing benefits of integrated cutting and welding with a multifunctional laser combi-head are described. Examples like the highly accurate and reproducible, combined cutting and welding of thin sheet assemblies, demonstrated e.g. in the sensorless production of non-linear TWBs, will be discussed. The integrated process chain improves productivity, flexibility and quality at a high cost-effectiveness. The laser sources used within the described applications comprise CO2 lasers as well as fiber-coupled solid-state lasers in the power range between 2 to 20 kW.