Robotic Laser Welding: ABB Robots From Torch to Fiber

For most of the twentieth century, cutting and joining steel meant a flame or an arc held by a skilled hand. Robotic laser welding has taken over a large share of that work in car plants and battery factories. A robot carries a processing head on the end of a fiber optic cable, and a beam focused to a fraction of a millimeter melts a narrow seam at high speed while putting little heat into the part. This post follows cutting and welding from the oxy-fuel torch to the CO2 laser and then to fiber lasers on robot arms, looks at what ABB robots such as the IRB 4600 and IRB 6620 do in laser cells, and asks where the process goes next.

An ABB robot cell for battery modules at ABB's plant in Baden, Switzerland. Photo: ABB

From the gas torch to the first cutting lasers

The gas torch came first. In 1903 the French engineers Edmond Fouché and Charles Picard developed a torch that burned acetylene with pure oxygen, hot enough to melt steel. For cutting, a jet of oxygen burns through steel that the flame has preheated. The kit is a pair of gas bottles, hoses and a trained hand, which is why shipyards, scrapyards and repair crews still use it. The weak points are heat and width. The flame heats a wide band of metal around the cut, thin sheet warps, and the edge usually needs grinding before anyone can weld it.

An oxy-acetylene welding torch made in France around 1906, shown at the Higgins Armory Museum. Photo: Daderot / Wikimedia Commons (public domain)

The laser came out of physics labs. Theodore Maiman ran the first working laser, a ruby crystal pumped by a flash lamp, at Hughes Research Laboratories in California in 1960. In 1964 Kumar Patel at Bell Labs built the carbon dioxide laser, whose infrared beam could be scaled up to high power. In 1967 Peter Houldcroft at The Welding Institute in Cambridge, England, blew oxygen along a focused CO2 beam and cut steel sheet 1 mm thick. Histories of the process usually treat that experiment as the start of laser cutting for industry.

Theodore Maiman with his new laser device in New York, July 1960. Photo: Associated Press via Wikimedia Commons (public domain)

CO2 lasers were awkward on robots. Their beam cannot travel through a glass fiber, so it had to be steered with mirrors inside jointed beam guides, or the part moved on a table under a fixed head. Most laser cutting therefore happened on flatbed machines, and robots took the jobs that needed a 3D path, such as trimming formed parts. Solid state lasers changed this because their light runs through a flexible fiber cable: first Nd:YAG lasers, later disk and fiber lasers. With a fiber cable the laser source sits in a cabinet, and a standard six axis robot carries only the optics.

A laser built in 1963 by Edward Damon at Ohio State University, on show at the National Museum of American History. Photo: Daderot / Wikimedia Commons (public domain)

Laser cells in battery plants and body shops today

In car body shops, robots with laser heads join roof seams, door rings and lids, and remote laser welding uses scanner optics to jump the beam from weld to weld while the robot keeps moving. Electric vehicles brought a lot of new laser work. Battery cell tabs and busbars, cell housings and the copper hairpins in electric motor stators are often laser welded, because the joints are small and heat must stay away from the cells. On 22 September 2026 the US Department of Energy described work at the Advanced Photon Source, where X-ray imaging showed how the flow of molten metal causes bumps, called humping, in high speed laser welds, and the team proposed an index to predict them.

A high power laser welding test at Lindoe Welding Technology, with gas nozzles around the weld. Photo: Krorc / Wikimedia Commons (CC BY-SA 3.0)

A week later, on 29 September, the Swiss lab Empa and the company Terra Quantum reported an AI model called LP-FNO that predicts the three dimensional melt pool of a laser process in milliseconds, up to 100,000 times faster than a conventional simulation. Fast models like this are a step toward a controller that corrects laser power and speed during the weld. ABB runs a laser welding cell in its own plant in Baden, Switzerland, which builds energy storage systems for electric vehicles. There an IRB 4600 robot places battery cells into modules and an IRB 6620 joins them by laser welding. ABB says the plant was commissioned with its RobotStudio simulation software.

An ABB robot working over battery modules in the cell at ABB's Baden plant. Photo: ABB

Other ABB robots fit laser work by size and payload. ABB lists laser and water jet cutting among the uses of the IRB 4600, and it names laser welding among the tasks of its larger IRB 6710 to IRB 6740 robots, which also carry spot welding guns in body shops. In September 2024 ABB added an Ultra Accuracy option for the GoFa cobot with a path accuracy of 0.03 mm and named laser welding of car parts and precision laser cutting as uses. Laser paths are usually generated from CAD data and tested offline, and a positioner run as one of the robot's external axes can turn the part so the head stays at the right angle.

An engineer with a GoFa cobot, the arm ABB offers with its Ultra Accuracy option. Photo: ABB

Where laser welding robots go next

Factories will keep adding fiber laser cells as battery formats and car platforms change, and most of the difficulty sits in the parts around the laser. A laser weld tolerates very small gaps, often a few tenths of a millimeter, so fixtures, stamped parts and robot paths all have to be accurate. More cells now carry seam finding cameras or sensors that look ahead of the beam, and the fast melt pool models from labs like Empa may let the controller adjust each weld as it happens. For battery packs, the same robot cell often places, clamps and welds, as in ABB's Baden line and in EV battery assembly generally.

A worker loads a fixture at a fenced robot cell in ABB's Baden battery plant. Photo: ABB

Safety sets laser cells apart from arc welding. A fiber laser beam is invisible, and a stray reflection can damage eyes well outside the cell, so robot laser cells are usually fully enclosed with laser safe walls and interlocked doors. That enclosure costs money and floor space, which keeps laser welding mostly in high volume plants. Handheld fiber laser welders have spread into smaller shops over the last few years, and trade magazines in August and September 2026 ran pieces on how to bring them in and on the safety risks that come with them.

A robot cutting with a laser under water at the Laser Zentrum Hannover stand, Hannover Messe 2016. Photo: NearEMPTiness / Wikimedia Commons (CC BY-SA 4.0)

Laser welding will not move into homes, but laser cutting already has: desktop CO2 and diode cutters for wood, acrylic and leather are common in schools, maker spaces and garages. Those machines teach skills that carry over to robot cells. Students who learn to plan a cutting path, set focus and power, and keep a beam inside an enclosure are learning the same ideas a laser cell programmer uses. In industry the beam power runs to kilowatts instead of watts, and a six axis robot replaces the small gantry that moves the head over a sheet of plywood.

A CNC laser cutting head working on wood at the Martin Guitar factory. Photo: Henrysz / Wikimedia Commons (CC BY 4.0)

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