Laser Welding

In contrast to heat conduction welding, deep penetration welding involves drilling an additional hole in the workpiece to be processed. This is used for welding at a certain depth. If a workpiece is in the focus of the laser and the steam produced by irradiation flows off, the resulting melt is displaced by the resulting pressure. A narrow, vapor-filled hole is formed at this depth, the so-called vapor capillary (also called keyhole). When the laser is guided along the weld seam, this vapor capillary moves with it and is completely surrounded by molten metal. The laser beam causes reflections on the molten walls of the vapor capillary. This relates to the absorption of the beam by the melt. The result is an increase in efficiency. Due to movement of the laser, covered areas cool down and then solidify. The result is a deep weld seam of high quality. Deep penetration welding is mainly used for materials of high thickness.

A high laser power and exact focusing of the laser beam are realized by high-quality optics. Special mirrors, high-precision lenses and compressed lens systems form the basic components for the creation of a powerful laser beam. Whether high reflectance, exact beam shaping and focusing or best image quality, our products promise consistently high performance, durability and effectiveness. The BeamTuning product range, for example, includes various laser beam shapers and expanders for transforming Gaussian laser beams into collimated and focused Top-Hat beams for various applications. Refinement of optical surfaces by high-end finishing processes can additionally perfect the results and ensure optimum results in laser welding.

The use of ultrashort pulse lasers allows a direct transition of a material into gaseous state. Material removal is achieved by ultrashort pulses in the range of picoseconds to femtoseconds. A necessary condition is an optimal focusing of the laser beam on the material to be processed. The advantage regarding material processing arises from material-protecting properties of the pulses. Due to the direct transition to the gaseous state, non-desirable melting, changes in microstructure and thermal stresses within the workpiece can be reduced to a minimum.