Pulse energy scaling of ps to ns pulses in highly integrated fiber amplifiers for micromachining

TIG welding is a common, industrially established process. Its main advantage is the weld quality. The drawback is lower process speeds which can lead to heat affects, irreversibly destroyed material properties and work piece distortion. To overcome these process limits, two common TIG processes were combined with low power laser radiation. This double TIG - laser process enables higher process speed and lower distortion without compromise in weld quality and penetration depth. Two electrodes are integrated into one welding head with the laser beam in the center. During the process the laser combines and guides the two electrical arcs to one common foot point on the work piece. Due to this increase of electric energy density, good process stability is achieved, even at higher welding speeds. The guiding of both electrical arcs with 400 W laser power and a beam diameter of 1.6 mm on the material surface will be demonstrated. Welding speeds up to 1 m/min were possible on aluminium. The paper shows first process results on aluminium with a material thickness of 2 mm. Welding samples, cross-sections, process images and the new welding head will be presented.