Thomas Opderbecke

TOPTIG: robotic TIG welding with integrated wire feeder

ALW has developed a new tungsten inert gas (TIG) robotic welding process which combines the quality of the TIG process with the productivity of the MIG process. The keystone is the particular configuration of the torch: the weld wire is fed directly into the arc zone, where the temperatures are higher resulting in ‘continuous liquid-flow’ transfer. This configuration also offers the advantage of reduced overall dimensions and greater accessibility of the torch for robotic welding of complex geometries. There is no longer any need to position and direct the weld wire with respect to the torch and the joint to be welded. Hence, the sixth axis of the robot is free. The applications to date relate to the welding of stainless steel containers, butt and lap welding, carbon steel mechanical parts with intermittent beads in the thin or medium thickness range. Applications on thin, galvanised sheeting, using CuSi3 wire with no spatter, have been successfully tested in the weld-brazing field, in partnership with the automobile industry. Other applications may include the welding of stainless steels and light alloys for the food and furniture sectors, among others.

Thin-sheet metal welding

Tungsten inert gas (TIG) welding is widely used in industry, mainly in manual applications and automatic welding. If the main advantage is its excellent weld quality, the main drawback is the welding speed and penetration compared with other welding processes. The TopTIG welding processes have been developed to improve robotized TIG welding, with the objective of combining TIG quality with MIG productivity. The key part of this new technology is an original torch concept: the wire feed is oriented at an angle close to the tungsten electrode and traversing the gas nozzle. This configuration provides the advantage of reduced overall dimensions and enhanced accessibility of the torch for robotic welding of complex geometries. There is also no need to maintain constant torch and wire feed orientation versus the joint axis, and in this way the sixth axis of the robot is liberated. Several technical features, such as an automatic electrode changer and a push–pull wire feeder, are associated with the new torch design. Applications have been developed for the braze welding of galvanized thin sheets with CuSi3 wires, without spatter. Other applications can be found in welding stainless steel or aluminium, such as in the food industry, manufacturing, furniture and bicycle production.