Laser welding with beam shaping – Latest application results

Recently, a new method of laser welding has been introduced. Currently it is starting with a leap in various industrial production tasks. This new welding method is based on applying a TRUMPF TruDisk thin-disk solid- state laser with a so called two-in-one fiber delivery optical cable BrightLine Weld. By means of this optical cable and in combination with a novel system of variable laser power coupling into the inner as well as the outer fiber core, an application-tailored laser power distribution is created. This enables a new degree of freedom through beam shaping for laser key-hole welding. The process benefits are significantly higher achievable feedrates during welding, without reaching the spatter regime associated with deep penetration welding of state of the art disk or fiber lasers.This report presents recent results from the welding of steel, aluminum and highly reflective materials such as copper. The welding of gear parts has been performed with beam shaping, utilizing the full feedrate performance with highly alloyed steels. Endurance strength tests based on test samples in multiple axial load configurations show that the weld seam characteristics of these novel high-speed welds fulfill state-of-the-art requirements.Furthermore, we present results in weld penetration depth monitoring, applying optical coherence tomography (OCT) to copper welding samples. Due to the key-hole stabilization in a wide range of feed rates and their respective penetration depths, the key-hole depth monitoring becomes widely applicable and supports the process especially in terms of reliability.