New Systems

Another challenge in the development of laser beam welding is the planning and qualification of new laser beam welding systems. One of such new systems currently employed at the BIAS is a Trumpf remote welding system.

Figure 1: Remot welding system with 6 kW Laser (Source:Trumpf Lasertechnik)

In this system, a CO2-Laser beam with very long focal length is focussed and deflected by fast-moving mirrors and then directed towards the workpiece from great distance. A unique feature of this system (Figure 2) is the available laser power of 6 kW in combination with a beam quality enabling the welding of steel and aluminium at focal lengths of up to 1500mm.

Figure 2: Overlap joint, zinc-coated steel (1,6 + 1,6 mm), gap 0,2 mm, P = 5 kW, f = 1500 mm, v = 3,5 m/min, shielding gas Helium

The main advantage of remote welding are positioning times significantly decreased (due to the higly dynamic beam deflection) as compared to conventional systems. Whereas nowadays in laser beam welding of short seams effective utilization time of the laser and the effective production time are small compared to the auxilliary process times mainly resulting from the handling of the welding head, positioning times of up to 700 m/min in remote welding enable a very fast sequential welding of spot welds or short seams. This is a special advantage for components with numerous short seams distributed over the workpiece, thus enabling an effective laser use of more than 90%. Thus, remote welding is a complementary process for existing laser applications and opens new field of application for the laser in such applications where nowadays e.g. resistance spot welding is preferably applied. Figure 2 shows as an example for potential applications an overlap joint of zinc-coated steel sheets.