High-speed micro welding of thin metal sheets

The diode pumped thin disk laser found large attention, recently. This relatively new laser concept combines the high efficiency and the good focusability of CO2-lasers with the short wavelength of YAG-lasers. The short wavelength enables fiber guided beam delivery and brings along advantages for the process such as higher absorptivity in metals and lower sensitivity to laser induced plasma. Due to its good focusability the thin disk layer is best suitable for laser beam micro welding of thin metal sheets. Up to now, this field of applications was reserved for pulsed laser systems. This contribution presents results of high speed micro welding of thin metal sheets with the thin disk laser. The advantages of high beam quality will be discussed in detail. As an example, with a focal spot of 100 μm keyhole welding was performed at travel speeds up to 40 m/min with best quality without any humping. The promisng results demonstrate the great potential of the thin disk laser in the field of micro welding of thin and ultra thin metal sheets.