Gap bridging ability in laser beam welding of thin aluminum sheets

The applicability of laser welding processes with its specific advantages, such as low distortion or production efficiency, is often limited when joining thin-walled aluminum components due to small gap bridging ability. To overcome this limit, a novel approach is presented using filler wire and a highly focused laser beam oscillation transverse to the welding direction. In the present work, the process development for welding in butt-joint configuration is shown. For this purpose, the influence of the welding speed, wire feed speed and beam oscillation parameters on wire melting behavior and on the welding result is presented. A process window for joining thin sheet material of 1 mm thickness with 1 mm joint gap is shown, and allowable tolerances for laser, wire and gap misalignment are investigated. Furthermore, the reached gap bridging ability of 1.9 mm for a constant gap and 3.15 mm for an opening gap configuration is shown in dependence of the utilized aluminum alloys. (C) 2014 Published by Elsevier B.V.