Welding of die-casted magnesium alloys for production

The importance of light weight magnesium alloys, especially for the automotive industry, has grown significantly during the last years. To fully benefit from the whole designing potential of this material, joining processes have to be developed. Laser beam welding turns out to be very suitable to join magnesium parts. The results of welding magnesium alloys AZ91HP and AM50HP with a 3 kW Nd:YAG laser and a 6 kW CO2 laser with an industrial robot and a gantry robot system are shown from a production point of view. The determination of the process window by analyzing the influence of laser type, power, welding velocity, and shielding gas, as well as the influence of the base material, leads to conclusions about process stability and production tolerances. Further investigations concerning fixturing techniques as well as seam preparation and joint geometry show effects on the process flexibility and the effort to realize high quality seams under production conditions. The investigated process parameters are evaluated mainly with respect to their influence on the static strength of the welding seam.