Hybrid is more than just laser plus MIG

Citation

(2002), "Hybrid is more than just laser plus MIG", Industrial Robot, Vol. 29 No. 2. https://doi.org/10.1108/ir.2002.04929baf.001

Hybrid is more than just laser plus MIG

Keywords: Welding, Laser, MIG, Hybrids

Just as the whole is often more than the sum of its parts, LaserHybrid is more than just a laser process plus a MIG (metal inert gas) welding process.

In the LaserHybrid system, the energy of the laser beam is directed to meet the plasma of the arc. The two act simultaneously on the same welding zone, influencing and assisting one another as they do so. In comparison with the results where each process is used separately, the outcome here is:

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  greater bridgeability, at the same time as very much higher joining rates

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  deeper penetration and narrow seams, yet less thermal input

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  high weld ductility, joint strength and scope for influencing the structure by means of the filler metal

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  greater process stability and machine availability

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  less work required for weld preparation and post-weld machining

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  reduced production times and costs, higher productivity

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  lower investment costs in relation to overall output

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  greater scope for improving weld appearance (design).

The system as a whole consists of a welding power source, the welding head and the process software (all from Fronius), together with commercially available robots and a laser source. Being the "heart" of the whole system, the welding head meets such requirements as: robot-compatible design, great flexibility in terms of its manoeuvrability, compact construction, good positionability of laser beam and arc with respect to one another, and – not least – a high degree of process reliability.

One of its special features is the way in which its MIG unit can be adjusted vis-a-vis the laser by up to 300 mm in the longitudinal axis. As well as this, it can also be adjusted in every Cartesian coordinate. The setting tolerance of the precision head is 0.1 mm, in all directions, meaning that either process can be optimally positioned with regard to the other. Coupled with the head's slender constructional form, this manoeuvrability in the longitudinal axis enables it to reach hard- to-access joining locations. Both the torch and the gas nozzle are water-cooled. Because the gas nozzle is cooled all the way down to its frontmost extremity, a 100 per cent duty cycle is possible at full laser power (4 kW) and arc amperage (250 A). The arc has its own gas atmosphere, independent of the laser; both work with the same shielding gas used in the MIG process. A crash-box (for collision protection) and an integral cross-jet with an extractor device round off the list of the main features of the new welding head.

The outlook for the LaserHybrid process

Fronius Development Chief Heinz Hackl is confident that the LaserHybrid process now being unveiled will be quick to establish itself in industry: "Firstly, applications where the laser has to work alongside a filler wire, and then all those joins that have hitherto been 'off-limits' to lasers on account of the weld- gap being too wide. It's also conceivable that in some areas, it will compete with twin-wire welding. As far as industrial sectors are concerned, I expect LaserHybrid to gain acceptance first in the automobile industry and its supplier firms, and in other production operations turning out large piece-numbers."

1. 1.

   The Fronius LaserHybrid welding head unites some interesting technical solutions, in particular for reaching hard- to-access joining locations (Plate 1).

   Plate 1

2. 2.

   In the LaserHybrid process, the constituent processes interact to influence and assist one another. This is why the new hybrid process offers very much more than just the sum of the individual processes that it comprises (Plate 2).

   Plate 2

   Contact: http://www.fronius.com