The intimate relationship that exists between a welder, the torch and the metal in manual applications is not one that’s been replicated by laser welding technology developers – at least not until recently. In most metal fabricating applications involving laser welding, human involvement typically is limited to programming a robot that wields a laser welding head that moves around a fixtured workpiece. That was until the hand-held laser welding system was introduced.
Laser welding allows for the joining of thick, thin, reflective and dissimilar metals. Welding of thick, thin, reflective, and dissimilar metal, which is difficult or even impossible with traditional arc welding methods, can be done with a laser.
Technology helps even novice welders get up to speed more quickly than they would with more traditional arc welding processes.
Because of the robust nature of the laser, metals don’t need to be pre-brushed or ground completely clean before welding takes place – saving you time and money on preparation work.
Laser welding isn’t new. The technology has proliferated for years in select industries like automotive, medical, defence, and aerospace. This includes OEMs and the suppliers that serve them. Even in this arena laser welding isn’t ubiquitous, but it isn’t rare either.
Still, venture outside these niches and into the general custom fabrication arena and you’ll find that laser welding remains a true rarity. Even if a fabricator does offer laser welding, it remains a fringe process, utilised for select jobs.
Arc welding remains the dominant way most fabrication shops that join two pieces of metal together. Why, exactly? Volumes may have been a concern in the past, but today plenty of custom fabricators have adopted robotic arc welding with great success. The dominant concerns now involve part fit-up and fixturing, and the fact that many parts have designs that don’t account for laser welding requirements.
Those challenges are real, but overcoming them isn’t as difficult as you might think. This is thanks to not only the evolution of laser welding, but also the accuracy of upstream processes, including laser cutting and bending, as well as some fresh approaches to fixturing.
Laser welding calls for fabricators to think anew, not just about weld gap tolerances or fixturing requirements, but about the entire process of metal fabrication.
The science of laser welding has come a long way. Like in cutting, welding with a laser comes down to analysing how a certain material absorbs the laser’s energy. Fibre lasers for welding and cutting behave much the same as they travel from the power source and through the delivery fibre.
The difference happens at the processing head. Positioned millimetres above the material surface, the cutting head focuses the beam and the assist gas (the laser’s “cutting tool”) evacuates molten material to create kerf. A fibre laser welding head operates farther from the material surface and focuses the beam in such a way as to achieve the optimal weld. And like in arc welding, laser welding uses gas (such as argon) to shield the weld from the atmosphere.
The laser forever changed the cutting department for custom fabricators, and it soon may do the same for the welding department.
In typical applications in custom fabrication, laser welding is autogenous. That is, it uses no filler metal. This reduces consumables costs and minimises post-weld finishing requirements. Thanks to concentrated heat input, a fast welding travel speed, and a minimal HAZ, most laser welded parts of a certain size are cool to the touch immediately after welding. These parts then can skip post-weld grinding, one of the most time-consuming processes on the shop floor. If parts do undergo subsequent polishing, it’s usually to meet a certain cosmetic requirement.
Introduction of Hugong hand-held swing laser welding machines
Hugong HGLW fibre laser welders are available in 1kW, 1.5kW and 2kW power source and have a maximum thickness weld of 8mm. The machines are a compact design and are fully assembled before shipment.
For further details contact TRM Supplies on TEL 011 974 7744 or visit www.trmsupplies.co.za