|During the 2010 Fabtech show, Lincoln Electric and IPG Photonics announced a strategic partnership for the development of HLAW welding systems. The promotion of HLAW by one of the world’s largest arc welding companies suggests a positive shift in how industries view the process.
History of HLAW
Having traditional welding companies embrace a laser based technology has not occurred overnight. The combination of a laser with an arc process to address some of the short comings of the technology is almost as old as laser processing itself. Bill Steen published a paper titled “Arc Augmented Laser Processing of Materials” in the Journal of Applied Physics as early as 1981. In most cases, the combination of the laser with an arc process was to address the fit up, chemistry, or power limitation of the laser. And while most hybrid processing has been centered on Gas Metal Arc Welding (GMAW) there have been others who have investigated combining lasers with Gas Tungsten Arc Welding (GTAW) (Diebold and Albright, Welding Journal, 1984) and plasma (Walduck and Biffin, Welding Research Aboard, 1995).
While HLAW has been investigated for a number of years, there were many reasons for its limited utilization. “I felt that a big disadvantage of the work that we were doing was that we were using a big clunky old laser that didn’t focus all that tightly,” says Vivian Merchant of his research efforts in the early 1990’s at the Canadian Defence Research Establishment. He added that their interest for using HLAW was to achieve higher production rates for military applications such as HY-80 material for submarine fabrication as well as for the welding of high strength materials for cross country pipelines. In addition, Vivian says that they recognized that, “Without the laser, it will take 10 passes to weld this one-inch-thick steel. With the laser, we can narrow the groove and weld it with only two passes!”
Even with “clunky” lasers, some applications did transition from the laboratory to the factory floor. Efforts in Germany with HLAW continued to be very active in the 1990’s. Researchers at The Welding and Joining Institute (ISF) of RWTH Aachen University worked with companies like Meyer Werft Shipbuilding of Papenburg, Germany to develop and assist in the implementation of the technology.
The result was the opening of a new panel line at Meyer Werft in 2000 for the welding of deck and bulkhead panels with stiffeners using HLAW with CO2 lasers. Not only did this represent a major acceptance of the technology, but required the development and acceptance of new specifications for shipbuilding by organizations such as DNV and Lloyds. Download Full Article