Laser-multi-pass-narrow-gap-welding of hot crack sensitive thick aluminum plates

Although the current process limitations for laser beam welding of thick aluminum plates (>10mm) have been overcome by high brilliant multi-kilowatt laser, there are still difficulties resulting from the material physical properties, e. g. the high heat conductivity, the large heat capacity and the high thermal expansion coefficient of aluminum. Especially for very deep weld seams, insufficient dilution of filler wire material in the root of the weld seam and the danger of hot cracks increases. With a new welding technology, the Laser-Multi-Pass-Narrow-Gap-Welding, a innovative approach has been developed to weld thick aluminum plates with highest beam quality lasers and remarkably reduced laser power. (C) 2013 The Authors. Published by Elsevier B.V. Selection and/or peer-review under responsibility of the German Scientific Laser Society (WLT e.V.)