Remote welding is a highly efficient laser process. By the use of a CO2-laser with a long focal length and a beam deflection by scanner optics, the laser beam is positioned and moved over the workpiece with high speed. By this technique, the overall processing time can be optimised by the reduction of secondary processing times. Today CO2- lasers with high power up to 6 kW are available with a beam quality which allows for the use of focal lengths up to 1500 mm.
In this study, the influence of the angle of incidence of the laser beam on the weld seam formation was investigated. In dependence on the position of the workpiece in the working area, this unavoidable and changing angle has an influence on the weld seam geometry, the joint cross section, and thus the strength of the joint. The investigations were concentrated on overlap and fillet joints on mild or zinc coated steel with the goal to define processing windows and strategies of workpiece positioning in the working area. In these investigations the influence of gaps caused by production were considered.
At welding with a laser power of more then 3 kW without process gas plasma shielding is initiated, which leads to a breakdown of the deep penetration welding process. The influence of shielding gas on the process and the way to deliver it to the interaction zone was investigated.