Saldatura con laser Nd:YAG di giunti di testa di lamiere sottili in lega di magnesio AZ31

Magnesium alloys are increasingly widespread in different industries such as automotive, electronic, etc. The wider use of these alloys may come with a reliable method of components joining. In this paper, the laser welding process using Nd:YAG laser of maximum power 2 kW has been investigated and reported. The effect of processing parameters including laser power and welding speed has been explored. Sheets with 1 mm thickness of a AZ31B magnesium alloy have been butt-welded with helium and argon used as shielding gas without filler material. Mechanical properties have been measured by means of uniaxial tensile tests using a Digital Image Correlation (DIC) technique for the strain measurement. After a preliminary experimental plan aimed at exploring the process parameters range, the welding process has been optimized using a Design of Experiment approach. Subsequent experimental plans have led to optimized butt joints that have showed, after tensile test, a sound weld bead with the fracture occurrence in the base material. The local strain analysis by DIC highlighted a different tensile behaviour, in terms of welding bead deformation, in optimized laser butt welded joints compared to the not optimized one.