Fiber laser-MIG hybrid welding of 5 mm 5083 aluminum alloy

Aluminum and its alloys are difficult to weld due to their specific characteristics. New joining methods such as high power fiber laser-MIG can provide higher overall productivity compared to the arc welding or laser beam welding. There is huge lack of information on how the specific welding parameters in laser arc hybrid welding affect quality of welds such as torch arrangement, distance between heat sources and shielding gas composition while other parameters were kept at constant. Laser-arc hybrid welds with short separation distance between sources produced severe porosity in one pass 5 mm thick aluminum alloy sheets welding due to unstable interactions and keyhole frequent collapses. Higher process stability and lower porosity level can be achieved by applying trailing torch arrangement. Addition of significantly more expensive helium to the shielding gas did not provide any benefits in terms of porosity decrease, process stability and mechanical properties of welds overall as was expected with selected welding parameters. (C) 2016 Elsevier B.V. All rights reserved.